Search results “Crypto cipher block size calculation”
DES algorithm follows the Feistel Structure Most of the Block cipher algorithms follows Feistel Structure BLOCK SIZE - 64 bits Plain Text No. of Rounds - 16 Rounds Key Size - 64 bits Sub Key Size - 48 bits No. of Sub Keys - 16 Sub Keys Cipher Text - 64 bits
Cipher Block Chaining Mode - Applied Cryptography
This video is part of an online course, Applied Cryptography. Check out the course here: https://www.udacity.com/course/cs387.
Views: 54710 Udacity
Vigenere Cipher - Decryption (Unknown Key)
This video shows the process (thoroughly) of how to find the key when you don't have it. English alphabet frequencies: http://www.math.cornell.edu/~mec/2003-2004/cryptography/subs/frequencies.html Decryption (known key): http://youtu.be/oHcJ4QLiiP8 Encryption: http://youtu.be/izFivfLjD5E
Views: 109197 Theoretically
Counter Mode - Applied Cryptography
This video is part of an online course, Applied Cryptography. Check out the course here: https://www.udacity.com/course/cs387.
Views: 20323 Udacity
SHA: Secure Hashing Algorithm - Computerphile
Secure Hashing Algorithm (SHA1) explained. Dr Mike Pound explains how files are used to generate seemingly random hash strings. EXTRA BITS: https://youtu.be/f8ZP_1K2Y-U Tom Scott on Hash Algorithms: https://youtu.be/b4b8ktEV4Bg http://www.facebook.com/computerphile https://twitter.com/computer_phile This video was filmed and edited by Sean Riley. Computer Science at the University of Nottingham: http://bit.ly/nottscomputer Computerphile is a sister project to Brady Haran's Numberphile. More at http://www.bradyharan.com
Views: 393678 Computerphile
How secure is 256 bit security?
Supplement to the cryptocurrency video: How hard is it to find a 256-bit hash just by guessing and checking? What kind of computer would that take? Cryptocurrency video: https://youtu.be/bBC-nXj3Ng4 Thread for Q&A questions: http://3b1b.co/questions Several people have commented about how 2^256 would be the maximum number of attempts, not the average. This depends on the thing being attempted. If it's guessing a private key, you are correct, but for something like guessing which input to a hash function gives a desired output (as in bitcoin mining, for example), which is the kind of thing I had in mind here, 2^256 would indeed be the average number of attempts needed, at least for a true cryptographic hash function. Think of rolling a die until you get a 6, how many rolls do you need to make, on average? Music by Vince Rubinetti: https://vincerubinetti.bandcamp.com/album/the-music-of-3blue1brown ------------------ 3blue1brown is a channel about animating math, in all senses of the word animate. And you know the drill with YouTube, if you want to stay posted on new videos, subscribe, and click the bell to receive notifications (if you're into that). If you are new to this channel and want to see more, a good place to start is this playlist: http://3b1b.co/recommended Various social media stuffs: Website: https://www.3blue1brown.com Twitter: https://twitter.com/3Blue1Brown Patreon: https://patreon.com/3blue1brown Facebook: https://www.facebook.com/3blue1brown Reddit: https://www.reddit.com/r/3Blue1Brown
Views: 803248 3Blue1Brown
Introduction to Side-Channel Power Analysis (SCA, DPA)
A complete introduction to side channel power analysis (also called differential power analysis). This is part of training available that will be available at http://www.ChipWhisperer.io shortly - also in person at Blackhat USA 2016 (see https://www.blackhat.com/us-16/).
Views: 10475 Colin O'Flynn
Bitcoin - Cryptographic hash function
What cryptographic hash functions are and what properties are desired of them. More free lessons at: http://www.khanacademy.org/video?v=0WiTaBI82Mc Video by Zulfikar Ramzan. Zulfikar Ramzan is a world-leading expert in computer security and cryptography and is currently the Chief Scientist at Sourcefire. He received his Ph.D. in computer science from MIT.
Views: 217388 Khan Academy
21. Cryptography: Hash Functions
MIT 6.046J Design and Analysis of Algorithms, Spring 2015 View the complete course: http://ocw.mit.edu/6-046JS15 Instructor: Srinivas Devadas In this lecture, Professor Devadas covers the basics of cryptography, including desirable properties of cryptographic functions, and their applications to security. License: Creative Commons BY-NC-SA More information at http://ocw.mit.edu/terms More courses at http://ocw.mit.edu
Views: 63486 MIT OpenCourseWare
AES Encryption 4: Matrix Multiplication
This is a short vid which shows the code for the matrix multiplication for the MixColumns step. I initially intended to make this vid and the previous AES one around the same length, but we actually covered almost everything in the previous vid! Mix Columns Wikipedia Page: https://en.wikipedia.org/wiki/Rijndael_mix_columns Code for dot products: tmp[0] = (unsigned char)(mul2[state[0]] ^ mul3[state[1]] ^ state[2] ^ state[3]); tmp[1] = (unsigned char)(state[0] ^ mul2[state[1]] ^ mul3[state[2]] ^ state[3]); tmp[2] = (unsigned char)(state[0] ^ state[1] ^ mul2[state[2]] ^ mul3[state[3]]); tmp[3] = (unsigned char)(mul3[state[0]] ^ state[1] ^ state[2] ^ mul2[state[3]]); tmp[4] = (unsigned char)(mul2[state[4]] ^ mul3[state[5]] ^ state[6] ^ state[7]); tmp[5] = (unsigned char)(state[4] ^ mul2[state[5]] ^ mul3[state[6]] ^ state[7]); tmp[6] = (unsigned char)(state[4] ^ state[5] ^ mul2[state[6]] ^ mul3[state[7]]); tmp[7] = (unsigned char)(mul3[state[4]] ^ state[5] ^ state[6] ^ mul2[state[7]]); tmp[8] = (unsigned char)(mul2[state[8]] ^ mul3[state[9]] ^ state[10] ^ state[11]); tmp[9] = (unsigned char)(state[8] ^ mul2[state[9]] ^ mul3[state[10]] ^ state[11]); tmp[10] = (unsigned char)(state[8] ^ state[9] ^ mul2[state[10]] ^ mul3[state[11]]); tmp[11] = (unsigned char)(mul3[state[8]] ^ state[9] ^ state[10] ^ mul2[state[11]]); tmp[12] = (unsigned char)(mul2[state[12]] ^ mul3[state[13]] ^ state[14] ^ state[15]); tmp[13] = (unsigned char)(state[12] ^ mul2[state[13]] ^ mul3[state[14]] ^ state[15]); tmp[14] = (unsigned char)(state[12] ^ state[13] ^ mul2[state[14]] ^ mul3[state[15]]); tmp[15] = (unsigned char)(mul3[state[12]] ^ state[13] ^ state[14] ^ mul2[state[15]]); Music Channel: Sober: https://youtu.be/Y2LCg3cGu7U Gold Digger: https://youtu.be/wAoXB8tg0co Become a patron and support What's a Creel programming vids on Patreon: www.patreon.com/whatsacreel FaceBook: www.facebook.com/pages/WhatsaCreel/167732956665435
Views: 15048 What's a Creel?
Block vs. Stream Ciphers - CompTIA Security+ SY0-401: 6.1
Security+ Training Course Index: http://professormesser.link/sy0401 Professor Messer’s Course Notes: http://professormesser.link/sy0401cn Frequently Asked Questions: http://professormesser.link/faq - - - - - Some data transfer methods will encrypt data one byte at a time or in groups of larger data blocks. In this video, you’ll learn how block ciphers combine data encryption with speed and efficiency. - - - - - Download entire video course: http://professormesser.link/401adyt Get the course on MP3 audio: http://professormesser.link/401vdyt Subscribe to get the latest videos: http://professormesser.link/yt Calendar of live events: http://www.professormesser.com/calendar/ FOLLOW PROFESSOR MESSER: Professor Messer official website: http://www.professormesser.com/ Twitter: http://www.professormesser.com/twitter Facebook: http://www.professormesser.com/facebook Instagram: http://www.professormesser.com/instagram Google +: http://www.professormesser.com/googleplus
Views: 48004 Professor Messer
Talk at crypto 2013. Author: Marc Stevens. See http://www.iacr.org/cryptodb/data/paper.php?pubkey=24643
Views: 402 TheIACR
Why the blocksize limit keeps BITCOIN free and decentralized
What is NAMECOIN BITCOIN'S First Fork http://youtu.be/oBkhPhu3_B4 Test Scanning Stainless Steel BITCOIN WALLET view http://youtu.be/P3Cny4iX-CM Why the blocksize limit keeps Bitcoin free and decentralized http://youtu.be/hJlJenB1CTE bitcoin jobs bitcoin jackpot bitcoin july 2014 bitcoin jerky bitcoin javascript bitcoin jokes bitcoin japan bitcoin jalapeno bitcoin json-rpc bitcoin jesus hacked j bitcointalk bitcoin j jb bitcoin faucet j r willett bitcoin spr/ bitcoin miner .j tomas j bitcoin bitcoin kurs bitcoin k?pa bitcoin kurs sek bitcoin konto bitcoin kr bitcoin krona bitcoin kurshistorik bitcoin kurs prognos bitcoin kraken bitcoin calculator john k bitcoin bitcoin k line bitcoin miner .k bitcointalk bitcoin k chart john k bitcointalk k ?emu je bitcoin k ?emu bitcoin alternativa k bitcoinu k ?emu slou?? bitcoin bitcoin live bitcoin lottery bitcoin logo bitcoin local bitcoin login bitcoin legal status bitcoin live value bitcoin litecoin bitcoin loans bitcoin laundry l bitcoin bitcointalk bitcoin miner .l l'ambassade bitcoin l'avenir du bitcoin l'histoire du bitcoin l'évolution du bitcoin l'origine du bitcoin peter l bitcoin l'inventeur du bitcoin bitcoin mining bitcoin mining calculator bitcoin market bitcoin mining software bitcoin mining pool bitcoin mixing service bitcoin map bitcoin mixer bitcoin market cap bitcoin mining calculator profit m bitcoin bitcoin m-pesa bitcoin mhash bitcoin m of n transactions sirius-m bitcoin bitcoin m of n bitcoin mt gox m etf bitcoin m got bitcoin m-pesa vs bitcoin bitcoin news bitcoin nyheter bitcoin nordic bitcoin norrman bitcoin node bitcoin norge bitcoin nedir bitcoin nasdaq bitcoin nakamoto bitcoin nordic flashback n bitcoin bitcoin miner .n bitcoin n-tv n shares bitcoin piotr_n bitcointalk m of n bitcoin w32/bitcoin miner.n tr/ bitcoin miner .n bitcoin omvandlare bitcoin online wallet bitcoin offline wallet bitcoin official site bitcoin otc bitcoin options bitcoin owner bitcoin original price bitcoin owners bitcoin open source code o bitcoin o bitcoinach bitcoin to usd wszystko o bitcoin sve o bitcoin bitcoin o que é bitcoin o co chodzi bitcoiny o co chodzi litecoin to bitcoin bitcoins o que é isso bitcoin ?sterreich bitcoin ?kning bitcoin ?verf?ring bitcoin ?kar bitcoin ?rebro bitcoin ?sterreich steuer bitcoin ?deme bitcoin ?sterreich kaufen bitcoin ?sszeomlott ludvig ?berg bitcoin bitcoin price, bitcoin price chart, bitcoin pool, bitcoin pris, bitcoin profit calculator, bitcoin poker, bitcoin paypal, bitcoin paper wallet, bitcoin preev, bitcoin program, p vs np bitcoin, bitcoin miner .p bitcoin p bitcoin price bitcoin p=np forum.bitcoin. pl bitcoin qt bitcoin qr code bitcoin qt synchronizing with network bitcoin qt wallet location bitcoin qt import wallet bitcoin qt synchronizing with network slow bitcoin qr bitcoin qt system requirements bitcoin qt trader bitcoin qt rescan bitcoin q a bitcoin q es bitcoins q son q son los bitcoins q es un bitcoin bitcoin rate bitcoin reddit bitcoin rig bitcoin register bitcoin r?knare bitcoin rich list bitcoin robbery bitcoin real time bitcoin raspberry pi mining bitcoin robot r bitcoin r/bitcoinmarkets r bitcoin subreddit r bitcoin reddit /r/ bitcoin circlejerk r bitcoin package r/ bitcoin mining r/bitcoin stocks /r/bitcointip r/ bitcoin beginners bitcoin sverige bitcoin sek bitcoin shop bitcoin swish bitcoin stock bitcoin skatt bitcoin store bitcoin statistics bitcoin stockholm bitcoin swedbank s bitcoin what is bitcoins bitcoin s curve gh/s bitcoin mh/s bitcoin th/s bitcoin mhash/s bitcoin 5 gh/s bitcoin miner th/s bitcoin miner gh s bitcoin miner bitcoin to sek bitcoin to usd bitcointalk bitcoin trading bitcoin ticker bitcoin tumbler bitcoin to paypal bitcoin trade bitcoin trend bitcoin trading bot t bitcoin bitcoin t shirt alpha-t bitcointalk buy bitcoin t shirt bitcoin to usd bitcoin t shirt uk bitcoin to euro bitcoin t-shirt shop bs t bitcoin bb&t bitcoin bitcoin usd bitcoin utveckling bitcoin usb miner bitcoin utopia bitcoin usd chart bitcoin uttagsautomat bitcoin url bitcoin users bitcoin uri bitcoin ubuntu u bitcoin /u/bitcointip /u/ bitcoin millionaire bitcoin u hrvatskoj bitcoin u srbiji bitcoinminer-u bitcoin u kune bitcoin u.s. dollar youtube bitcoin bitcoin u bosni bitcoin value bitcoin value chart bitcoin v?rde bitcoin value sek bitcoin valuta bitcoin v?xla bitcoin valutakurs bitcoin value history bitcoin v?rde graf bitcoin virus bitcoin v hyper-v bitcoin bitcoin v sloveniji bitcoin to usd litecoin vs bitcoin bitcoin v ?esku bitcoin vs dollar gold vs bitcoin bitcoin v bratislava bitcoin v ?r bitcoin wallet bitcoin wiki bitcoinwisdom bitcoin worth bitcoin wikipedia bitcoin wallet android bitcoin webhallen bitcoin watch bitcoin worth graph bitcoin wallet windows w bitcoin bitcoin w polsce bitcoin w niemczech bitcoin w chinach bitcoin w chmurze bitcoin w praktyce bitcoiny w polsce
Views: 171 bitcoin showing
[M19] Cryptography - Hash Calc
Next http://youtu.be/VTVRV03bPAk = Summary below = Module 01 - Phases of Penetration Testing * The 5 Phases of Penetration Testing http://youtu.be/uQrrSMXAujM Module 02 - Footprinting * Introduction http://youtu.be/8buGxgHxGnw * Whiteboard http://youtu.be/bw1CBD2GkKM * AnyWho http://youtu.be/G7mC3q07jek * nsLookup http://youtu.be/tRh0ngHXLZA * Path Analyzer Pro http://youtu.be/rIKNapdyoMQ * Ping http://youtu.be/wJDuOjnr2AM Module 03 - Scanning * Introduction http://youtu.be/w7QnSUGs10w * Whiteboard http://youtu.be/yxwQ8Ejsi7c * DNS Enumeration http://youtu.be/fvtPz7oa79E * DNS Overview and Zone Transfers http://youtu.be/oIptO0B6tlw * hPing3 http://youtu.be/KKRXf0gONAk * nikTo http://youtu.be/QWl5IQpjPYU * Performing a nMap scan http://youtu.be/zc5m0I6vpeA * Web Data Extraction http://youtu.be/9w-TXWQ-GFY Module 04 - Enumeration * Introduction http://youtu.be/CzRZOInKWMs * Whiteboard http://youtu.be/zinRkzQs2lY * GetAcct http://youtu.be/YzYAt3gvFcE * nbtStat http://youtu.be/NkafHmFqRPk * netDiscover http://youtu.be/A4REMvk5cYY * NetUse http://youtu.be/8ID7kXPmXjs * Null Session http://youtu.be/5i21VwUv1zI * Password List http://youtu.be/PWA1EZoeFqM * PsTools http://youtu.be/etM-YhlelDs * smbClient http://youtu.be/3sQVLSAf2Ls * SuperScan http://youtu.be/VXggfeAnh4U Module 05 - System Hacking * Introduction http://youtu.be/97Pnidm0mSk * Whiteboard http://youtu.be/AMUNiwqX19Y * ADS Spy http://youtu.be/E1l3JEmuPqA * How is Alternate Data Stream used to hack http://youtu.be/p_U8TrR1AK4 * Link Control Protocol http://youtu.be/aqz9NGElW04 * pwdump http://youtu.be/MjTMFS0TdfI * sethC http://youtu.be/RbdjED-cQOk * snow http://youtu.be/aCaH5zvs6XI * x.exe http://youtu.be/YWezjrEhv-E Module 06 - Trojans * Introduction http://youtu.be/y0tHtnZIUYQ * Whiteboard http://youtu.be/0UZOcgZOHUg * fPort http://youtu.be/fUO6V1wMHyY * ICMPserv http://youtu.be/-LpMonzRZ88 * MD5 http://youtu.be/qWC6NuKItLs * netStat http://youtu.be/In6cwOAvnH4 * PRCView http://youtu.be/GACOCDLKQcw * TcpView http://youtu.be/IWVjTORNE7E * Tini http://youtu.be/wQ4AGVFKjGU Module 07 - Viruses & Worms * Introduction http://youtu.be/8kgxoe_A-zQ * Whiteboard http://youtu.be/cK8-Tm_81mQ * bintext 1/2 http://youtu.be/3nCNEzaopB0 * bintext 2/2 http://youtu.be/_gYiRGg7sPY * DelME http://youtu.be/akbO89YwsrU * Internet Worm Maker Thing http://youtu.be/oCri9EbPpLA * JPS http://youtu.be/ynrO3QmsT_o Module 08 - Sniffing Traffic * Introduction http://youtu.be/HQYip9pFkcw * Whiteboard http://youtu.be/qLsH-NaiCVk * Driftnet http://youtu.be/6jV0uYZJSfg * macof http://youtu.be/xGrzcxObF64 * SMAC http://youtu.be/a5BFng9xy-E * tshark http://youtu.be/fNf80veMjVI * urlsnarf http://youtu.be/5DC22if9faE * WebSpy http://youtu.be/-CkSEnrUmbM Module 09 - Social Engineering * Introduction http://youtu.be/axV6WCTWyNs * Whiteboard http://youtu.be/JlcUMfvPti8 Module 10 - Denial of Service * Introduction http://youtu.be/5N-_F28tnig * Whiteboard http://youtu.be/eOUwOQdMp3U * hping3 http://youtu.be/K4_Ag-CgfEM * LOIC http://youtu.be/DPDwd5Ay2d4 Module 11 - Session Hijacking * Introduction http://youtu.be/MKGYTQsIPWs * Whiteboard http://youtu.be/qQtf3amzwJM * Ferret http://youtu.be/NiZlmTLgaLw * Hamster http://youtu.be/yx_jDMqdB10 Module 12 - Hacking Web Servers * Introduction http://youtu.be/cqB7rpBAal8 * Whiteboard http://youtu.be/m94oP96q3rE * dirbuster http://youtu.be/2tOQC68hAcQ * WPScan http://youtu.be/p6k3ozYY-NM Module 13 - Web Applications * Introduction http://youtu.be/t6jJTKqreE0 * Whiteboard http://youtu.be/5VSVKIEnEE8 * burpSuite http://youtu.be/rh2pvWcsLIY * HTTPRecon http://youtu.be/xBBHtS-dwsM * IDServe http://youtu.be/7qb9p_Hs6wo * nikTo http://youtu.be/xOliB8koo9I * VirusTotal http://youtu.be/3q5xYX_EhHE * wget http://youtu.be/kCmUipDn-Uc Module 14 - SQL Injection * Introduction http://youtu.be/9uwG0SEfd94 * Whiteboard http://youtu.be/PmRKHTSpWS8 * BlindElephant http://youtu.be/gzVdMd6l_js * phpID http://youtu.be/uZdHDNXMQkE * sqlmap http://youtu.be/SfpmPxMyJLA Module 15 - Wireless * Introduction http://youtu.be/QtMeTVNmeM4 * Whiteboard http://youtu.be/fbWWnRkuAnw * airodump-ng http://youtu.be/98bFAqzGfdI * airomon http://youtu.be/dNqIybLB0Q0 * Kismet http://youtu.be/Qvd0Hh6FQPM Module 16 - Mobile Hacking * Introduction http://youtu.be/VMoIGWXNhow * Whiteboard http://youtu.be/Ms3q3Qi2kBQ Module 17 - IDS, Firewalls & Honeypots * Introduction http://youtu.be/7oaagKAvu4U * Whiteboard http://youtu.be/WOw6hbX7jlk Module 18 - Buffer Overflows * Introduction http://youtu.be/3TW_XAJbxdI * Whiteboard http://youtu.be/YjSmGTYv4WY * make, compile, run http://youtu.be/aT3OPCBJSTM * stack http://youtu.be/0jQHKtJc_uI Module 19 - Cryptography * Core Principles of Cryptography http://youtu.be/guCfp2tI704 * Whiteboard http://youtu.be/tmoHJbghBoQ * Advanced Encryption Package http://youtu.be/08ZvcjDUf20 * CrypTool http://youtu.be/kH8UY7f2TQM * Hash Calc http://youtu.be/qDxGoRuVQwk * HashMyFiles http://youtu.be/VTVRV03bPAk Source http://bit.ly/1J6jhd1
Views: 1039 Nicolas Quenault
Symmetric Key and Public Key Encryption
Modern day encryption is performed in two different ways. Check out http://YouTube.com/ITFreeTraining or http://itfreetraining.com for more of our always free training videos. Using the same key or using a pair of keys called the public and private keys. This video looks at how these systems work and how they can be used together to perform encryption. Download the PDF handout http://itfreetraining.com/Handouts/Ce... Encryption Types Encryption is the process of scrambling data so it cannot be read without a decryption key. Encryption prevents data being read by a 3rd party if it is intercepted by a 3rd party. The two encryption methods that are used today are symmetric and public key encryption. Symmetric Key Symmetric key encryption uses the same key to encrypt data as decrypt data. This is generally quite fast when compared with public key encryption. In order to protect the data, the key needs to be secured. If a 3rd party was able to gain access to the key, they could decrypt any data that was encrypt with that data. For this reason, a secure channel is required to transfer the key if you need to transfer data between two points. For example, if you encrypted data on a CD and mail it to another party, the key must also be transferred to the second party so that they can decrypt the data. This is often done using e-mail or the telephone. In a lot of cases, sending the data using one method and the key using another method is enough to protect the data as an attacker would need to get both in order to decrypt the data. Public Key Encryption This method of encryption uses two keys. One key is used to encrypt data and the other key is used to decrypt data. The advantage of this is that the public key can be downloaded by anyone. Anyone with the public key can encrypt data that can only be decrypted using a private key. This means the public key does not need to be secured. The private key does need to be keep in a safe place. The advantage of using such a system is the private key is not required by the other party to perform encryption. Since the private key does not need to be transferred to the second party there is no risk of the private key being intercepted by a 3rd party. Public Key encryption is slower when compared with symmetric key so it is not always suitable for every application. The math used is complex but to put it simply it uses the modulus or remainder operator. For example, if you wanted to solve X mod 5 = 2, the possible solutions would be 2, 7, 12 and so on. The private key provides additional information which allows the problem to be solved easily. The math is more complex and uses much larger numbers than this but basically public and private key encryption rely on the modulus operator to work. Combing The Two There are two reasons you want to combine the two. The first is that often communication will be broken into two steps. Key exchange and data exchange. For key exchange, to protect the key used in data exchange it is often encrypted using public key encryption. Although slower than symmetric key encryption, this method ensures the key cannot accessed by a 3rd party while being transferred. Since the key has been transferred using a secure channel, a symmetric key can be used for data exchange. In some cases, data exchange may be done using public key encryption. If this is the case, often the data exchange will be done using a small key size to reduce the processing time. The second reason that both may be used is when a symmetric key is used and the key needs to be provided to multiple users. For example, if you are using encryption file system (EFS) this allows multiple users to access the same file, which includes recovery users. In order to make this possible, multiple copies of the same key are stored in the file and protected from being read by encrypting it with the public key of each user that requires access. References "Public-key cryptography" http://en.wikipedia.org/wiki/Public-k... "Encryption" http://en.wikipedia.org/wiki/Encryption
Views: 427207 itfreetraining
Crypto & Block Cipher Modes (OpenSSL, AES 128, ECB, CBC)
Video also at http://www.irongeek.com/i.php?page=videos/crypto-block-cipher-modes-openssl-aes-128-ecb-cbc with notes
Views: 17356 Adrian Crenshaw
Cipher Feedback Mode - Applied Cryptography
This video is part of an online course, Applied Cryptography. Check out the course here: https://www.udacity.com/course/cs387.
Views: 32643 Udacity
Number of keys for ideal block cipher (Statistics Examples 8)
Counting the number of possible keys for an ideal block cipher that takes 64 bits of plaintext in.
Views: 3338 Steven Gordon
Ever wonder how Bitcoin (and other cryptocurrencies) actually work?
Bitcoin explained from the viewpoint of inventing your own cryptocurrency. Videos like these made possible by patreon: https://patreon.com/3blue1brown Protocol Labs: https://protocol.ai/ Interested in contributing? https://protocol.ai/join/ Special thanks to the following patrons: http://3b1b.co/btc-thanks Some people have asked if this channel accepts contributions in cryptocurrency form as an alternative to Patreon. As you might guess, the answer is yes :). Here are the relevant addresses: ETH: 0x88Fd7a2e9e0E616a5610B8BE5d5090DC6Bd55c25 BTC: 1DV4dhXEVhGELmDnRppADyMcyZgGHnCNJ BCH: qrr82t07zzq5uqgek422s8wwf953jj25c53lqctlnw LTC: LNPY2HEWv8igGckwKrYPbh9yD28XH3sm32 Supplement video: https://youtu.be/S9JGmA5_unY Music by Vincent Rubinetti: https://soundcloud.com/vincerubinetti/heartbeat Here are a few other resources I'd recommend: Original Bitcoin paper: https://bitcoin.org/bitcoin.pdf Block explorer: https://blockexplorer.com/ Blog post by Michael Nielsen: https://goo.gl/BW1RV3 (This is particularly good for understanding the details of what transactions look like, which is something this video did not cover) Video by CuriousInventor: https://youtu.be/Lx9zgZCMqXE Video by Anders Brownworth: https://youtu.be/_160oMzblY8 Ethereum white paper: https://goo.gl/XXZddT Music by Vince Rubinetti: https://vincerubinetti.bandcamp.com/album/the-music-of-3blue1brown ------------------ 3blue1brown is a channel about animating math, in all senses of the word animate. And you know the drill with YouTube, if you want to stay posted on new videos, subscribe, and click the bell to receive notifications (if you're into that). If you are new to this channel and want to see more, a good place to start is this playlist: http://3b1b.co/recommended Various social media stuffs: Website: https://www.3blue1brown.com Twitter: https://twitter.com/3Blue1Brown Patreon: https://patreon.com/3blue1brown Facebook: https://www.facebook.com/3blue1brown Reddit: https://www.reddit.com/r/3Blue1Brown
Views: 2205585 3Blue1Brown
Changing grid block size
Full course at: http://johnfoster.pge.utexas.edu/PGE323M-ResEngineeringIII/course-mat
Padding - Applied Cryptography
This video is part of an online course, Applied Cryptography. Check out the course here: https://www.udacity.com/course/cs387.
Views: 3337 Udacity
Explanation of Index of Coincidence
Part 2 of extended explanations of cryptanalysis techniques discussed in ASU's CSE 465 Information Assurance class. The lecture slide mentioned is available at https://docs.google.com/presentation/d/12nESJSKTn0oAFJ0C17oIMZcywgnpL7cCeLxsmn6fZro/pub?start=false The URL for my senior project is http://csilm.usu.edu/~securityninja/index.psp Created with TechSmith Snagit for Google Chrome™ http://goo.gl/ySDBPJ
Views: 4949 Mike Mabey
Cryptography: Crash Course Computer Science #33
Today we’re going to talk about how to keep information secret, and this isn’t a new goal. From as early as Julius Caesar’s Caesar cipher to Mary, Queen of Scots, encrypted messages to kill Queen Elizabeth in 1587, theres has long been a need to encrypt and decrypt private correspondence. This proved especially critical during World War II as Allan Turing and his team at Bletchley Park attempted to decrypt messages from Nazi Enigma machines, and this need has only grown as more and more information sensitive tasks are completed on our computers. So today, we’re going to walk you through some common encryption techniques such as the Advanced Encryption Standard (AES), Diffie-Hellman Key Exchange, and RSA which are employed to keep your information safe, private, and secure. Note: In October of 2017, researchers released a viable hack against WPA2, known as KRACK Attack, which uses AES to ensure secure communication between computers and network routers. The problem isn't with AES, which is provably secure, but with the communication protocol between router and computer. In order to set up secure communication, the computer and router have to agree through what's called a "handshake". If this handshake is interrupted in just the right way, an attacker can cause the handshake to fault to an insecure state and reveal critical information which makes the connection insecure. As is often the case with these situations, the problem is with an implementation, not the secure algorithm itself. Our friends over at Computerphile have a great video on the topic: https://www.youtube.com/watch?v=mYtvjijATa4 Produced in collaboration with PBS Digital Studios: http://youtube.com/pbsdigitalstudios Want to know more about Carrie Anne? https://about.me/carrieannephilbin The Latest from PBS Digital Studios: https://www.youtube.com/playlist?list=PL1mtdjDVOoOqJzeaJAV15Tq0tZ1vKj7ZV Want to find Crash Course elsewhere on the internet? Facebook - https://www.facebook.com/YouTubeCrash... Twitter - http://www.twitter.com/TheCrashCourse Tumblr - http://thecrashcourse.tumblr.com Support Crash Course on Patreon: http://patreon.com/crashcourse CC Kids: http://www.youtube.com/crashcoursekids
Views: 167301 CrashCourse
AskDeveloper Podcast - 46 - Cryptography - Part 1 - Introduction and Hashing - التشفير الجزء الأول
http://www.askdeveloper.com/2017/01/cryptography.html Information Security 1. Introduction ○ Security by obscurity § Steganography □ Hiding data inside another form of data, like using non-used bits in image to hide a message § Cool, but not practical. § Disadvantages ◊ Algorithm secrecy vs. key secrecy ○ Cryptography is everywhere and yet if done right, you can barely see it. ○ Goals: § Confidentiality □ Secrets stay secret. § Integrity □ Data is not tampered with. § Non-Repudiation □ No party can deny sending messages. § Authentication □ Each party can ensure that the sender is what they expect. ○ Cryptography § Hashing § Encryption § Signing § Protocols ○ Random Number Generators § Extremely important, almost all encryption/hashing strength is affected by how random the random number generator is. § Don't use simple random number, use a cryptographic random number generator with a sophisticated source of entropy. § Pseudorandom number generator § Dual_EC_DRBG random generator backdoor 2. Body ○ Hashing (one Way) § Properties □ Fixed length output no matter what size the input was □ Very easy to compute the hash of a given message, however very hard to compute from a hash the corresponding input. □ Mathematically infeasible to generate a message that has a given hash □ Any modification to a message produces a completely different hash that has no relationship to the original message's hash. □ It is mathematically infeasible to find two messages with the same hash. Hash Collision § Hashing Functions □ Provides data integrity, however lacks authentication □ Examples ® MD5 ◊ Considered Insecure ® Secure Hash Family SHA-X, Sha-1, Sha-2 [Sha256, Sha512], Sha-3 ◊ Sha-1 is considered insecure. ◊ Sha-1, Sha-2 designed by NSA ◊ Sha-3 is not designed by NSA, Competition winner. □ Attacks ® Brute force ◊ CPU's are getting faster and cheaper every day. ◊ GPU's are getting faster and cheaper every day. ◊ Special Hash calculating hardware is becoming more available especially with the BitCoin push. ® Rainbow table attacks ◊ Pre-Calculated tables where you can reverse lookup a hash to a value ◊ Try www.crackstation.net § Hash Message Authentication Codes (HMAC) □ Adds authentication to integrity □ Can be used with all previous algorithms, HMACMD5, HMACShA1, HMAC256 … etc. § Salted Hash □ Adds random salt to mitigate rainbow table □ Salts are unique per record, and not a secret. § Password Based Key Derivation Function (PBKDF2) □ RSA Public Key Cryptographic Standard PKCS #5 Version 2.0 □ Internet Engineering Task Force RFC 2898 Specification ® Adds a lot of iterations to slow it just enough to mitigate brute force (default 50,000 iterations) ® Adds random salt to mitigate rainbow table □ Disadvantage: It can be easily implemented with hardware which makes it vulnerable to bruteforce even with high number of iterations § Bcrypt □ Password Hashing function □ State of the art password hashing § Usages □ Integrity Check Password Storage Our facebook Page http://facebook.com/askdeveloper On Sound Cloud http://soundcloud.com/askdeveloper Please Like & Subscribe
Views: 2034 Mohamed Elsherif
Dr. Peter Rizun - Block Propagation and the Z-parameter
OnChain Scaling Conference presentation June 24/16 "Block Propagation and the Z-parameter" www.onchainscaling.com [email protected]
Views: 457 OnChain Scaling
What is Hashing & Digital Signature in The Blockchain?
What is Hashing & Digital Signature in The Blockchain? https://blockgeeks.com/ Today, we're going to be talking about the word blockchain and breaking it down to understand what does it mean when someone says, "Blockchain." What is hashing? Hashing refers to the concept of taking an arbitrary amount of input data, applying some algorithm to it, and generating a fixed-size output data called the hash. The input can be any number of bits that could represent a single character, an MP3 file, an entire novel, a spreadsheet of your banking history, or even the entire Internet. The point is that the input can be infinitely big. The hashing algorithm [00:01:00] can be chosen depending on your needs and there are many publicly available hashing algorithms. The point is that the algorithm takes the infinite input of bits, applies some calculations to them, and outputs a finite number of bits. For example, 256 bits. What can this hash be used for? A common usage for hashes today is to fingerprint files, also known as check zones. This means that a hash is used to verify that a file has not been [00:01:30] tampered with or modified in any way not intended by the author. If WikiLeaks, for example, publishes a set of files along with their MD5 hashes, whoever downloads those files can verify that they are actually from WikiLeaks by calculating the MD5 hash of the downloaded files, and if the hash doesn't match what was published by WikiLeaks, then you know that the file has been modified in some way. How does the blockchain make use of hashes? [00:02:00] Hashes are used in blockchains to represent the current state of the world. The input is the entire state of the blockchain, meaning all the transactions that have taken place so far and the resulting output hash represents the current state of the blockchain. The hash is used to agree between all parties that the world state is one in the same, but how are these hashes actually calculated? The first hash is calculated for the first block [00:02:30] or the Genesis block using the transactions inside that block. The sequence of initial transactions is used to calculate a block hash for the Genesis block. For every new block that is generated afterwords, the previous block's hash is also used, as well as its own transactions, as input to determine its block hash. This is how a chain of blocks is formed, each new block hash pointing to the block hash that came before it. This system of hashing guarantees that no transaction in the history can be tampered with because if any single part of the transaction changes, so does the hash of the block to which it belongs, and any following blocks' hashes as a result. It would be fairly easy to catch any tampering as a result because you can just compare the hashes. This is cool because everyone on the blockchain only needs to agree on 256 bits to represent the potentially infinite state of the blockchain. The Ethereum blockchain is currently tens of gigabytes, but the current state of the blockchain, as of this recording, is this hexadecimal hash representing 256 bits. What about digital signatures? Digital signatures, like real signatures, are a way to prove that somebody is who they say they are, except that we use cryptography or math, which is more secure than handwritten signatures that can be [00:04:00] easily forged. A digital signature is a way to prove that a message originates from a specific person and no one else, like a hacker. Digital signatures are used today all over the Internet. Whenever you visit a website over ACTPS, you are using SSL, which uses digital signatures to establish trust between you and the server. This means that when you visit Facebook.com, your browser can check the digital signature that came with the web page to verify that it indeed originated from Facebook and not some hacker. In asymmetric encryption systems, users generate something called a key pair, which is a public key and a private key using some known algorithm. The public key and private key are associated with each other through some mathematical relationship. The public key is meant to be distributed publicly to serve as an address to receive messages from other users, like an IP address or home address. The private key is meant to be kept secret and is used to digitally sign messages sent to other users. The signature is included with the message so that the recipient can verify using the sender's public key. This way, the recipient can be sure that only the sender could have sent this message. Generating a key pair is analogous to creating an account on the blockchain, but without having to actually register anywhere. Pretty cool. Also, every transaction that is executed on the blockchain is digitally signed by the sender using their private key. This signature ensures that only the owner of the account can move money out of the account.
Views: 21021 Blockgeeks
Password Cracking - Computerphile
'Beast' cracks billions of passwords a second, Dr Mike Pound demonstrates why you should probably change your passwords... Please note,at one point during the video Mike suggests using SHA512. Please check whatever the recommended process is at the time you view the video. How NOT to Store Passwords: https://youtu.be/8ZtInClXe1Q Password Choice: https://youtu.be/3NjQ9b3pgIg Deep Learning: https://youtu.be/l42lr8AlrHk Cookie Stealing: https://youtu.be/T1QEs3mdJoc http://www.facebook.com/computerphile https://twitter.com/computer_phile This video was filmed and edited by Sean Riley. Computer Science at the University of Nottingham: http://bit.ly/nottscomputer Computerphile is a sister project to Brady Haran's Numberphile. More at http://www.bradyharan.com
Views: 1295906 Computerphile
Views: 20770 Jeff Suzuki
DEF CON 23 - Crypto and Privacy Village - Carlson and Doherty - Breaking CBC
Breaking CBC, or Randomness Never Was Happiness Dr. Albert H. Carlson (ECCSmith) & Patrick Doherty Hiding patterns in encrypted messages to make the transmission look like random symbols is the goal of cryptography. However, all ciphers do not completely disguise those patterns, making decryption possible. In response to this problem, modes were introduced to break up patterns and to increase the “randomness” of an encrypted message. In the case of Cipher Block Chaining mode (CBC) the randomizing material is the cipher text from the preceding block. CBC uses a “feed forward” algorithm and a regular structure that provides attackable data. In fact, there is so much information in the structure and associated data that CBC wrapped around ANY cipher can be efficiently broken. We show that by using the blocks of the CBC algorithm both linear and non-linear encryptions using CBC can be broken. Further, we show that no linear cipher (such as a permutation or XOR cipher) is safe when used in conjunction with the mode and that non-linear ciphers (such as AES) are also vulnerable. Using the Birthday Paradox to predict how much data is needed to allow for decryption. This talk will demonstrate the break and show the mathematical background of the attack. BIO: Dr. Albert Carlson began his hacking career soon after he began taking programming courses in High School in Chicago in 1975. Upon completion of his BSCompEng degree from the University of Illinois at Urbana in 1981, he joined the US Army as a Military Intelligence Officer specializing in Electronic Warfare and Cryptography. Retiring due to injury, he then began a 25 year career in engineering that included work in consumer, military, and designing utility substation security systems. Dr. Carlson returned to school at the University of Idaho in 2002. There he completed his Master’s degree and PhD, both in Computer Science and specializing in Advance Set Theory and Cryptography. His dissertation, accepted in June of 2012, had as its’ subject: applying Set Theoretic Estimation to decryption. In 2013 Dr. Carlson joined the faculty of Fontbonne University on the staff of the Math and Computer Science department. His research team studies the use of patterns in natural language and how they relate to set and information based attacks on ciphers. Dr. Carlson’s research interests include: cryptography, set theoretic estimation, natural language, patterns in language, physical security, critical infrastructure protection, and hardware security. Patrick Doherty is a senior at Fontbonne University and will graduate in December of 2015. He is majoring in Computer science and plans on earning a graduate degree in the same field. He is the Project manager for the Research team.
Views: 2382 DEFCONConference
Block Cipher Standards (DES)
Cryptography and Network Security by Prof. D. Mukhopadhyay, Department of Computer Science and Engineering, IIT Kharagpur. For more details on NPTEL visit http://nptel.iitm.ac.in
Views: 29344 nptelhrd
Securing Stream Ciphers (HMAC) - Computerphile
Bit flipping a stream cipher could help you hit the Jackpot! But not with HMAC. Dr Mike Pound explains. Correction : "pseudo" is spelled incorrectly on the graphic. http://www.facebook.com/computerphile https://twitter.com/computer_phile This video was filmed and edited by Sean Riley. Computer Science at the University of Nottingham: http://bit.ly/nottscomputer Computerphile is a sister project to Brady Haran's Numberphile. More at http://www.bradyharan.com
Views: 98581 Computerphile
RSA Cipher Explained
Euclid's Algorithm Link: [Coming Soon] in the mean time use this link: http://www.asakusuma.com/euclidean/euclidean.php Another animated attempt of explaining the RSA cipher (public key cryptography aka asymmetric key cryptography). This tutorial includes rules of the cipher followed by an example to clear things up. This video talks mostly about encrypting blocks size of two text and will briefly skim over the methods in encrypting larger block sizes. This was a part of my final year project to create a learning aid. I decided to upload this so the animation won't go to waste. All feedbacks welcome. Do note: this video is meant for people who already have basic knowledge of the RSA cipher and is a part of an application created for my dissertation. Special thanks for Olivia Beck for creating the background image Facebook: http://tinyurl.com/kennyplaysguitar Twitter: https://twitter.com/kenwinlam
Views: 43024 Kenny Luminko
Correlation Power Analysis (CPA) on AES Algorithm
Experimental Setup the AES-128 algorithm in FPGA (Sakura-X) and it's power analysis attack. Download the AES Verilog code: http://satoh.cs.uec.ac.jp/SAKURA/hardware/SAKURA-X.html
Views: 401 Ali Akbar
Block Cipher Standards (AES)
Cryptography and Network Security by Prof. D. Mukhopadhyay, Department of Computer Science and Engineering, IIT Kharagpur. For more details on NPTEL visit http://nptel.iitm.ac.in
Views: 18279 nptelhrd
AskDeveloper Podcast - 47 - Cryptography - Part 2 - Encryption
الحلقة السابقة https://www.youtube.com/watch?v=FcKxlOuGq2U ○ Encryption (Two Ways) § Symmetric Encryption □ Same key both encrypts and decrypts the data. □ Very fast, yet exchanging key is tricky □ Very Algorithmic □ Examples ® DES Data Encryption Standard (BROKEN) ◊ Uses key of 56 bit length ® Triple DES (3DES) ◊ Uses three keys (or two unique keys) of 56 bit each ® AES Advanced Encryption Standard ◊ Uses keys of 128, 192 or 256 bits long □ Attacks ® Brute force ◊ Usually mitigated via increasing key length, as difficulty increases exponentially as key size increases, for example time to crack given a modern super computer. Key Size Time To Crack 56 bits 399 seconds 128 bits 1.02 * 1018 years 192 bits 1.87 * 1037 years 256 bits 3.31 * 1056 years ◊ Side-Channel Attacks § Asymmetric Encryption □ Key pairs have mathematical relationship □ Each one can decrypt messages encrypted by the other. □ Slow, but exchanging key is trivial □ Very Mathematical □ Anyone can know the Public Key ® The Public key can only be used to encrypt data □ The Private key is kept secret, and never leaves the recipient's side. ® The Private key can only be used to decrypt data □ Examples ® RSA (Rivest, Shamir and Adelman) ® The de-facto standard in the industry ® Public and Private keys are based on large Prime Numbers § Hybrid Encryption □ Uses both Symmetric and Asymmetric encryption at the same time. □ Goals: ® Use the performance of Symmetric Crypto ® Convenience of sharing keys using Asymmetric Crypto ® HMAC for authentication. □ Steps: (Order is very important) ® Party 1 (Alice) 1. Generates a random AES Session Key (32 bytes / 256 bits) 2. Generates a random Initialization Vector (IV) (16 bytes / 128 bits) 3. Encrypt the message to be sent using the AES Session Key & IV 4. Calculate an HMAC of the encrypted message using the AES Session key 5. Encrypt the AES Session Key using the Public Key of Party 2 (Bob) The recipient. 6. Sends a packet of (Encrypted Message, Encrypted Session Key, Initialization Vector, and HMAC) to Bob ® Party 2 (Bob) 1. Decrypts Session key using his Private Key 2. Recalculates the HMAC of the encrypted message (Validates message integrity) } If HMAC check pass – Decrypts the message using the decrypted AES Session Key and Initialization Vector } Otherwise, rejects the message because of integrity check failure. Our facebook Page http://facebook.com/askdeveloper On Sound Cloud http://soundcloud.com/askdeveloper Please Like & Subscribe
Views: 682 Mohamed Elsherif
Symmetric Key Ciphers
Cryptography and Network Security by Prof. D. Mukhopadhyay, Department of Computer Science and Engineering, IIT Kharagpur. For more details on NPTEL visit http://nptel.iitm.ac.in
Views: 17515 nptelhrd
IOTA tutorial 9.1: Key, Digests and Address
If you like this video and want to support me, go this page for my donation crypto addresses: https://www.youtube.com/c/mobilefish/about This is part 19.1 of the IOTA tutorial. In this video series different topics will be explained which will help you to understand IOTA. It is recommended to watch each video sequentially as I may refer to certain IOTA topics explained earlier. The generation of a key, digests and address, all starts with a seed. How the key is calculated, see: https://github.com/iotaledger/iota.crypto.js/blob/v0.4.2/lib/crypto/signing/signing.js var key = function(seed, index, length) Every index number refers to an address, also known as public key, and each address has a corresponding unique key, also known as the private key. seed is a randomly generated 81 trytes (A-Z9), converted to trits (81x3=243 trits) index is an integer (0,1,2 .. 9007199254740991) and every address has a corresponding index number. length is the security level (1,2 or 3) Security level 1: key has 1x27 = 27 segments, each segment consists of 81 trytes. key has in total 27 x 81 = 2187 trytes Security level 2: key has 2x27 = 54 segments, each segment consists of 81 trytes. key has in total 2 x 27 x 81 = 2 x 2187 = 4374 trytes Security level 3: key has 3x27 = 81 segments, each segment consists of 81 trytes. key has in total 3 x 27 x 81 = 3 x 2187 = 6561 trytes Security level 1, key size = (2187 x 3 x ln(3) / ln(2)) / 8 = ~1300 bytes Security level 2, key size = (4374 x 3 x ln(3) / ln(2)) / 8 = ~2600 bytes Security level 3, key size = (6561 x 3 x ln(3) / ln(2)) / 8 = ~3900 bytes How the digests is calculated, see: https://github.com/iotaledger/iota.crypto.js/blob/v0.4.2/lib/crypto/signing/signing.js var digests = function(key) Security level 1, digests size = 1x243 = 243 trits = 243 / 3 = 1 x 81 trytes Security level 2, digests size = 2x243 = 486 trits = 486 / 3 = 2 x 81 trytes Security level 3, digests size = 3x243 = 729 trits = 729 / 3 = 3 x 81 trytes How the address is calculated, see: https://github.com/iotaledger/iota.crypto.js/blob/v0.4.2/lib/crypto/signing/signing.js var address = function(digests) Security level 1, address = hash(digests[0-242]) Security level 2, address = hash(digests[0-485]) Security level 3, address = hash(digests[0-728]) Address size is always 243 trits = 243 / 3 = 81 trytes Check out all my other IOTA tutorial videos: https://goo.gl/aNHf1y Subscribe to my YouTube channel: https://goo.gl/61NFzK The presentation used in this video tutorial can be found at: https://www.mobilefish.com/developer/iota/iota_quickguide_tutorial.html #mobilefish #howto #iota
Views: 1113 Mobilefish.com
Perfect secrecy | Journey into cryptography | Computer Science | Khan Academy
Claude Shannon's idea of perfect secrecy: no amount of computational power can help improve your ability to break the one-time pad Watch the next lesson: https://www.khanacademy.org/computing/computer-science/cryptography/crypt/v/random-vs-pseudorandom-number-generators?utm_source=YT&utm_medium=Desc&utm_campaign=computerscience Missed the previous lesson? https://www.khanacademy.org/computing/computer-science/cryptography/crypt/v/case-study-ww2-encryption-machines?utm_source=YT&utm_medium=Desc&utm_campaign=computerscience Computer Science on Khan Academy: Learn select topics from computer science - algorithms (how we solve common problems in computer science and measure the efficiency of our solutions), cryptography (how we protect secret information), and information theory (how we encode and compress information). About Khan Academy: Khan Academy is a nonprofit with a mission to provide a free, world-class education for anyone, anywhere. We believe learners of all ages should have unlimited access to free educational content they can master at their own pace. We use intelligent software, deep data analytics and intuitive user interfaces to help students and teachers around the world. Our resources cover preschool through early college education, including math, biology, chemistry, physics, economics, finance, history, grammar and more. We offer free personalized SAT test prep in partnership with the test developer, the College Board. Khan Academy has been translated into dozens of languages, and 100 million people use our platform worldwide every year. For more information, visit www.khanacademy.org, join us on Facebook or follow us on Twitter at @khanacademy. And remember, you can learn anything. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy’s Computer Science channel: https://www.youtube.com/channel/UC8uHgAVBOy5h1fDsjQghWCw?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 131242 Khan Academy Labs
Shannons Theory
Cryptography and Network Security by Prof. D. Mukhopadhyay, Department of Computer Science and Engineering, IIT Kharagpur. For more details on NPTEL visit http://nptel.iitm.ac.in
Views: 9339 nptelhrd
IOTA tutorial 9: Address and checksum
If you like this video and want to support me, go this page for my donation crypto addresses: https://www.youtube.com/c/mobilefish/about This is part 9 of the IOTA tutorial. In this video series different topics will be explained which will help you to understand IOTA. It is recommended to watch each video sequentially as I may refer to certain IOTA topics explained earlier. The procedure to generate IOTA addresses is as follows: IOTA addresses are deterministically generated starting with the seed (81 trytes). Seed (trytes): C9RQF ... QIAWT Convert the seed (81 trytes) to trits (= 81 x 3 = 243 trits) Seed (trits): 0,1,0,0,0,0 ... -1,-1,0,-1,1,-1 Every address has a corresponding key index number. A key index number is an integer starting from 0. Address 0 has key index number 0, address 1 has key index number 1, etc. They key index number always starts with integer 0, and is simply incremented in order to get the next address. The largest key index number allowed is 9007199254740991. This largest key index number is the same as 2^53 - 1, which is the same as the Javascript constant: Number.MAX_SAFE_INTEGER An IOTA seed can generate in total 9007199254740992 addresses. The decimal key index number must be converted to trits. For example the key index number 1 converted to trits looks like: 1,0,0 Next create a subseed by adding the key index number and seed together. subseed = seed + key index number IOTA provides 3 security levels: 1, 2 or 3. A security level determines the number of rounds for hashing, which means that a single seed can have 3 different accounts. A different security level with the same index number, means that you will get a different address. Security level 1, Key size (trits): 6561 x 1 Remark: Used for low security (for very high efficiency). Best for tiny IoT devices that only transact/store small amounts of value. Security level 2, Key size (trits): 6561 x 2 Remark: Used for standard security (for medium performance). Best for regular people's wallets and devices that store higher amounts of value. Security level 3, Key size (trits): 6561 x 4 Remark: Used for full blown quantum proof security that conforms to National Security Agency’s (NSA) recommendations for sensitive material. Good for big value transactions and paranoids. Client libraries, such as iota.lib.js makes it possible to choose another security level. See: https://www.mobilefish.com/services/cryptocurrency/iota_wallet.html By default the IOTA light wallet uses security level 2 and you can not change its security level. If you created an address using security level 1 or 3 this address will not appear in the IOTA light wallet using the same seed. In the next slide a simplistic explanation is given how the subseed is hashed multiple times using the Keccak-384 hash algorithm. The hashing is done in a wrapper class called Kerl. The seed and subseed can differ between the first 1 tryte up to and including 12 trytes. If someone else has exactly the last 69 (= 81 - 12) trytes up to and including 81 trytes of your seed they can see the balance of one or more of your addresses. The probability that someone else happens to have the same last 69 trytes of your seed is very small. Here is the proof: IOTA seed with only 69 trytes has 27^69 = 5.80 x 10^98 possible combinations. For comparison: A Bitcoin private key with 256 bits has 2^256 = 1.15 x 10^77 possible combinations. This means, even if you have an IOTA seed with only 69 trytes it has more possible combinations than a Bitcoin private key. A checksum is an additional 9 trytes added to an address (81 trytes) which can be used to validate the integrity and validity of the address. An address with checksum is 90 trytes long, 81 trytes for the address itself and 9 trytes for the checksum. The procedure to calculate an address checksum is as follows: Start with an IOTA address (81 trytes).Address (trytes): FSAFM ... NVDZC Convert the address (81 trytes) to trits (= 81 x 3 = 243 trits) Address (trits): 1,0,-1,1,0,-1 ... -1,0,0,0,1,0 The address is hashed using the Keccak-384 hash algorithm. Convert the address checksum (243 trits) to trytes (81 trytes): ...PJFNYWVUGKPRTRV Get the last 9 trytes: VUGKPRTRV Append the last 9 trytes to the original address: FSAFM ... NVDZCVUGKPRTRV The address including checksum has a length of 81 + 9 = 90 trytes. The IOTA light wallet: Always creates addresses including the checksum. The addresses are always 90 trytes long. Always requires receive addresses, with valid checksums when making a transaction. The receive addresses must be 90 trytes long. Check out all my other IOTA tutorial videos: https://goo.gl/aNHf1y Subscribe to my YouTube channel: https://goo.gl/61NFzK The presentation used in this video tutorial can be found at: https://www.mobilefish.com/developer/iota/iota_quickguide_tutorial.html #mobilefish #howto #iota
Views: 2549 Mobilefish.com
Prime Numbers as Building Blocks - Euclid's greatest discovery
Euclid identified Prime Numbers as building blocks for all numbers. This leads to the discovery of unique factorization. This idea lies at the heart of modern encryption techniques such as RSA.
Views: 17409 Art of the Problem
Albrecht Petzoldt - The Cubic Simple Matrix Encryption Scheme
Albrecht Petzoldt of TU Darmstadt presented a talk titled: The cubic simple matrix encryption scheme at the 2014 PQCrypto conference in October, 2014. Abstract: In this paper, we propose an improved version of the Simple Matrix encryption scheme of PQCrypto2013. The main goal of our construction is to build a system with even stronger security claims. By using square matrices with random quadratic polynomials, we can claim that breaking the system using algebraic attacks is at least as hard as solving a set of random quadratic equations. Furthermore, due to the use of random polynomials in the matrix A, Rank attacks against our scheme are not feasible. PQCrypto 2014 Book: http://www.springer.com/computer/security+and+cryptology/book/978-3-319-11658-7 Workshop: https://pqcrypto2014.uwaterloo.ca/ Find out more about IQC! Website - https://uwaterloo.ca/institute-for-qu... Facebook - https://www.facebook.com/QuantumIQC Twitter - https://twitter.com/QuantumIQC
[GreHack 2016] Improving dm-crypt performance for XTS-AES mode – Levent Demir
Using dedicated hardware is common to accelerate crypto- graphic operations: complex operations are managed by a dedicated co- processor, and data is transferred between RAM and the crypto-engine through DMA operations. The CPU is therefore free for other tasks, which is vital in embedded environments with limited CPU power. In this work we discuss and benchmark XTS-EAS, using either software or mixed approaches, using Linux and dm-crypt, and a low power AT- MEL board, featuring an AES crypto-engine that supports ECB-AES but not the XTS-AES mode. We show that the dm-crypt module used in Linux for full disk encryption has limitations that can be relaxed when considering higher block sizes. We demonstrate that performance gains almost by a factor two are possible, which opens new opportunities for future use-cases.
Views: 187 GreHack
Cryptography: Transposition Cipher
This lesson explains how to encrypt and decrypt a message using a transposition cipher. Site: http://mathispower4u.com
Views: 52118 Mathispower4u
How the blockchain is changing money and business | Don Tapscott
What is the blockchain? If you don't know, you should; if you do, chances are you still need some clarification on how it actually works. Don Tapscott is here to help, demystifying this world-changing, trust-building technology which, he says, represents nothing less than the second generation of the internet and holds the potential to transform money, business, government and society. TEDTalks is a daily video podcast of the best talks and performances from the TED Conference, where the world's leading thinkers and doers give the talk of their lives in 18 minutes (or less). Look for talks on Technology, Entertainment and Design -- plus science, business, global issues, the arts and much more. Find closed captions and translated subtitles in many languages at http://www.ted.com/translate Follow TED news on Twitter: http://www.twitter.com/tednews Like TED on Facebook: https://www.facebook.com/TED Subscribe to our channel: http://www.youtube.com/user/TEDtalksDirector
Views: 1264009 TED
DES -- The Algorithm
DES -- Data Encryption Standard -- has been the workhorse of modern cryptography for many decades. It has never been compromised mathematically (not in the open literature, at least), yet, its design notes were never made public either. Many who use it are unaware of how it works. Here we open the DES box and find inside a repetition of sub-boxes in which very simple primitives are at work: substitution, transposition, split, concatenation, and bit-wise operation. DES inside teaches us that complexity is comprised of a lot of simplicity.
Views: 137010 Gideon Samid
How to solve problems on Galois Field
I have taken few problems as an example, how to approach and solve, on galois field. link to my channel- https://www.youtube.com/user/lalitkvashishtha link to data structure and algorithm playlist - https://www.youtube.com/watch?v=GbOW74e4xZE&list=PLLvKknWU7N4y_eGpQdg1Y-hORO7cxtoLU link to information theory and coding techniques playlist - https://www.youtube.com/watch?v=2qJ_mcjKYtk&list=PLLvKknWU7N4yDkIlN4YE-sXfFD4trDf6W link to compiler design playlist - https://www.youtube.com/watch?v=uAVkjTbB7Yc&list=PLLvKknWU7N4zpJWLqk7DXK26JwTB-gFmZ
Views: 7552 Lalit Vashishtha
Nexus: Taking Blockchain into the Future
Phoenix, Arizona, December 13, 7:00 pm – Colin Cantrell, the designing architect and engineer for the cryptocurrency Nexus (NXS), http://nexusearth.com will be making a presentation to the Phoenix Blockchain Meetup on the deficiencies and limitations of Bitcoin and how his visionary next generation cryptocurrency Nexus, will carry cryptocurrency into the future. Bitcoin’s greatest limitation is in the fact that it is designed to be a trustless system, yet requires trust to use. This trust requirement is in the centralized mining pools, the politics, security of exchanges and online wallets, and the way the protocol operates with honest and dishonest nodes. Bitcoin also suffers from centralized mining using ASIC computers from giant mining operations. This puts the control of Bitcoin in the hands of only a select few operators. Nexus was designed to be highly resistant to centralized control. Nexus uses a combination of Nexus Proof of Stake (nPOS) and 2 forms of proof of work algorithm: CPU mining by looking for dense prime clusters of numbers that are 308 digits long, and GPU mining calculating a hash using Skein and Keccak of 1024 bits making Nexus ultra resistant in cryptographic strength and long term use as quantum computers to continue to reach more people. Nexus seeks to mitigate these issues with new architecture, new developmental technologies, and new physical infrastructure in order to take blockchains and crypto currencies into the future. Some other notable security features of Nexus is private keys that are 571 bit that can be 2.5 times the length of bitcoins but in retrospect multitudes stronger than what bitcoin uses which is 256 bit. Skein and Keccak hashing are also acting together to secure each other in the respect that if one of them becomes more insecure from partial or full collisions being found like SHA1 and some of the SHA2 hashing that is currently in use, it provides a fallback for the security of the second algorithm helps to secure the primary. Bitcoin started off as an experiment sent out on a mailing list, where many thought that it never could work due to many failures in the Digital Currency front. Blockchain technology is now an integral part of the future; moving humanity away from the obsolete systems of centralized control. Bitcoin can be compared to the vacuum tube which were used for the earliest giant sized computers and radio amplifiers, Nexus is the transistor that makes it possible to have a super computer in our pockets. Colin is an entrepreneur and innovator who used his years of experience in the aerospace industry and 13+ years of Software Engineering to develop the necessary solutions for the growth of the technological base of Crypto Currencies. Since 2014 he has been developing Nexus, after becoming involved in Bitcoin in early 2013. He also is researching and developing new energy systems that will contribute to more sustainability in the future including hydrogen, electromagnetics, provides humanity with the technology that lowers our cost of life while increases the quality of life. Nexus is currently one of the top 100 Cryptocurrencies and is positioned itself as the next generation of cryptocurrency designed to dramatically improve the blockchain model by being able to handle more transactions, faster confirmations, 3-way decentralized block production, as well as significantly stronger encryption than Bitcoin.
Views: 1611 Morpheus Titania
RSA ALGORITHM with Example
Hello Friends in this video i have explained RSA [Rivet Shamir Adleman] Algorithm. I explained this example with two prime numbers 3 and 11 and whole calculation is included in video. I hope all of you can easily understand from the video. Please post your valuable suggestions which will help me to improve my videos.
Views: 7568 Dhruvin Shah
Let's Talk Crypto 002: Terminology
School Of Crypto Facebook Group: http://soc.fyi/fbgroup School Of Crypto Website: http://schoolofcrypto.com Twitter: https://twitter.com/SchoolOfCrypto_ Subscribe to the podcast on iTunes: http://soc.fyi/itunes Grab all the show notes for this episode here: https://schoolofcrypto.com/podcast/crypto-terminology-ltc002/ Terminology Short punchy episode to discuss some of the terminology used in the world of Crypto. This episode is designed to be short, so you can reference back to it at any stage as your Learn and Earn !!! Crypto - Short for cryptography. Short version is scrambling plain text into cipher text to secure the information. The science of coding and decoding to keep messages secure. Encryption: The use of cryptography to encode a message such that only the intended recipient(s) can decode it. Bitcoin uses encryption to protect wallets from unauthorized access. FOMO - Fear of Missing Out FUD - Fear and Uncertainty and Doubt “Fear, uncertainty and doubt (often shortened to FUD) is a disinformation strategy used in sales, marketing, public relations, talk radio, politics, religious organizations, and propaganda.” Block Chain - a digital ledger in which transactions made in bitcoin or another cryptocurrency are recorded chronologically and publicly. P2P - Peer-to-peer. This ‘new; digital currency network is designed for each one of us to be our own bank. There is no 3rd party involved. BULL VS BEAR Markets Described by the way animals attack. Bull thrusts its horns up, while a BEAR swipes it paws downward Bull market - Where prices are rising or expecting to rise. Bear Market - Falling prices and shrouded in pessimism. ASIC Mining vs GPU Mining - Different Types of mining for different types of coins as they are built on different algorithms. ASIC - Application Specific Integrated Circuit (Exactly what it is, specifically designed for the BITCOIN SHA256 algorithm) GPU - Graphics Processor Unit (Video card found in computers but in this instant HIGH End gaming cards as they have high processing and fast memory speeds onboard). Hash Rate - How many Hashes per second. Hash function is a mathematical process that takes input data of ayn size, performs and operation on it, and returns output data of a fixed size. It's a measure of how many cryptographic calculation per second, which affect your rewards. --------------------------------------------------------------------- Exchange - This is where you exchange normal $$$ for Crypto Currency (ie buy BITCOIN) but you can also trade different currencies. Similar to the stock market. Wallets - This is where you store your currency (coins). Certain wallets support certain coins and will have some upcoming reviews in future episodes. Address - Location on where to send your coins. Also called your PUBLIC Address. Similar to your Letter Box. Public Key Private Key ICO’s - Short of Initial Coin Offering. Compared to IPO (Initial Public Offering) conventional world where companies offer shares in their business. PONZI Schemes - This operation generates returns for older investors through revenue paid by new investors, rather than legitimate business activities or profit of financial trading. We need to LOOK OUT for these. There are many surfacing and closing all the time. Satoshi: The smallest divisible unit of one bitcoin. There are 100 million satoshis (8 decimal places) in one bitcoin. One satoshi = 0.0000001 bitcoins. Public Key - Is like to your PO Box or post box. Publicly known and visible and people can make deposits Private Key - Special key that controls access to the mailbox. ANYONE with this key can access your mailbox (ie Wallet) so KEEP IT SAFE !!! ALWAYS.
Views: 3 School Of Crypto