- Видео 10
- Просмотров 723 085
Daniel Rees
Добавлен 28 ноя 2013
Monoalphabetic Shift/Caesar Cipher
Monoalphabetic Shift/Caesar Cipher Encryption and Decryption
Просмотров: 67 335
Видео
Public Keys Part 2 - RSA Encryption and Decryptions
Просмотров 129 тыс.10 лет назад
Asymmetric Part 2 - RSA includes tutorial on how to encrypt and decrypt as well as calculating the keys and euclidean algorithm.
Public Keys Part 1 - Public Key Introduction and El Gamal
Просмотров 19 тыс.10 лет назад
Asymmetric Part 1 - Introduction to Public Key and El Gamal's Key Distributions
Introduction to Cryptography
Просмотров 1,5 тыс.10 лет назад
Introduction to Cryptography, includes Modular Arithmetic and Numerical Representation tutorial
Polyalphabetic Part 1 - Vigenere Encryption and Kasiski
Просмотров 59 тыс.10 лет назад
Polyalphabetic Part 1, (Vigenere Encryption and Kasiski Method
Polygraphic Part 2 - Hill Ciphers Examples/Encryption/Decryption
Просмотров 131 тыс.10 лет назад
A beginner's guide to Polygraphic Ciphers, Part 2. (Hill Ciphers Examples/Encryption/Decryption)
Polygraphic Part 1 - Playfair Ciphers Encryption/Decryption
Просмотров 83 тыс.10 лет назад
A beginner's guide to Polygraphic Ciphers Part 1 (Playfair Cipher Encryption/Decryption
Stream Ciphers - Encryption/Decryption
Просмотров 78 тыс.10 лет назад
A beginner's guide to Stream Ciphers (Encryption/Decryption).
Polyalphabetic Part 2 - Friedman Decryption
Просмотров 11 тыс.10 лет назад
A beginner's guide to Polyalphabetic Ciphers Part 2 (Friedman Decryption)
Transposition Ciphers - Encryption/Decryption
Просмотров 146 тыс.10 лет назад
A beginner's guide to Transposition Ciphers (Encryption/Decryption).
The decryption key 'd' must be a positive value. -17 isn't positive. In modular arithmetic, a number and its equivalent positive counterpart both satisfy the same condition. Therefore -17mod40 = 40-17 = 23 becomes our decryption key instead.
Extremely well explained. I love how it sounds like a film reel from the 1950s.
Who can Break this uncompressed public key 😂 1btc 1BDvQZjaAJH4ecZ8aL3fYgTi7rnn3o2thE Pubkey 04ea0d6650c8305f1213a89c65fc8f4343a5dac8e985c869e51d3aa02879b57c60cff49fcb99314d02dfc612d654e4333150ef61fa569c1c66415602cae387baf7
31 becomes 5 I don't know!!
Simple, clear explanation. Thank you.
i dont understand how she got the common values from 1=5-2(7)+2(5) to 1=3(5)-2(7) ???
Plz answer it --1lJsySvgkkCE9VFNYVR1sblc4z1YxphmCSF2A38KczfbjLO9xxZPzaSrzIeXZm0r6Fiuxf6AEbCOMgNaECP4Czk39oOYDOeyjmSHtN9ZPAEsHhtbJ05cze5xuJkYnolyD57YI5LnufH3m25Y2Z1p5UNotZdHeo7Hj3uTX88gcF0px4dmS4DLNg2875EaiBHtt4cf2am4
Plz anybody answer it..
Few videos teach about this method however it was a meticulous way to understand it well
Thanks a lot Daniel! This one was very informative. Could you please do a video on monoalphabetic with permutation.
Why is e = 7?
it was picked such that the greatest common divisor (GCD) between e and phi(N) was 1 aka they had no common divisor besides 1
How do you calculate 28^23 using calculate to get decimal. Im getting exponential figures
I think you might have to do clever algebra to cancel things, cause my calculator is doing the same thing and getting an error.
U explained it well I understood thanx
Your numbers confuse me lols xD for me A=1 M=13, N=14 Z=26, - I would only use 0 if coding with a PC as PC's love to count from 0 on up, but as a Human I count 1 on up, no biggie, if the number is larger than 26, I just subtract 26! "Also" Tip, MEET ME AT NOON coulda been shifted to "T ME AT NOON MEE" Then you cipher and one time pad it lols xD, It's a bit more secure as shifting can sometimes break up words and a single letter at the beginning may look like " I, or A" as EOUY is usually not a word, equally the shift causes a 3 letter word to appear at the end... So then when you Encrypt it, it then looks like 5 separate words, 1st being 1 letter the next 2 at 2, the 4th at 4 and the 5th at 3 letters. Then ofc you would cipher and OTP this. Another way to do this is since there is 12 letters you could also do, "ETME ATNO ONME" and what this does is make 3 words appear as 4 letters each from what would normally be 4 words, then ofc you would Cipher and then OTP it. You can even "Transposition" Cipher this too, As 12 Letters is divisible by 2,3,4,6 so yeah you literally can do anything, do keep in mind though that a Computer Algorithm has likely mapped this simple 12 letter text out in many ways so like chuck in an extra letter "X" and an Encoding Keyword and then take that message and apply it then to the method you wanna do. ;)
Or another thing you can do which may seem odd is convert all letter into a 6 "Bit" Binary number then for each set 000 to 111 assign those each a Letter then take your original letter Example lets say "R" which might be 001 001 Then if you had X=001 for instance you could write like an X on Page 1, but also an X on Page 3 or something of the message you may be sending, stuff like this is harder to break as then you can use your One Time Pads you had set for each page actually on the pages themselves xD This effectively makes every letter multidimensional and even that much harder to crack.
I like your video for stream cipher, but how to determine the decryption process?
you just misplaced the numerical represetations of c and d.
Fantastic thank you very much!
What happened to SA row 3?
You gave me exactly what I was looking for. Thank you so much. Hope you have an amazing day <3
Vigenere Ciphers were heavily utilized by the South during America's previous Civil War
Finally, a complete explanation delivered by a mathematician! Thanks a lot! Your work is highly appreciated.
So why will 3rd party person not be able to decrypt like Alice???
very smart of take 2 * 2 matrix and get rid of complications of higher order matrix
Thanks alot!
The Zodiac 340 cipher involves a combination of transposition cipher & substitution cipher
Thank you! (Minor detail: letter W is the 23rd letter of the alphabet, ref. 5:05).
Thank you very much, easy to understand 👌
1lJsySvgkkCE9VFNYVR1sblc4z1YxphmCSF2A38KczfbjLO9xxZPzaSrzIeXZm0r6Fiuxf6AEbCOMgNaECP4Czk39oOYDOeyjmSHtN9ZPAEsHhtbJ05cze5xuJkYnolyD57YI5LnufH3m25Y2Z1p5UNotZdHeo7Hj3uTX88gcF0px4dmS4DLNg2875EaiBHtt4cf2am4
Been looking for this video, finally found it again.
I realize it is kind of randomly asking but do anyone know of a good website to stream new tv shows online ?
@Kamryn Shepherd I dunno I'd suggest flixportal. just search on google after it :) -mekhi
@Mekhi Wesson Thank you, I signed up and it seems to work :) I appreciate it !!
@Kamryn Shepherd happy to help =)
very good explaining and solving. thanks
Lmao that transposition explanation
What if trying to encrypt "red" or "redx" and you get "slk" what does the x pair up with if it is at the very bottom, and same column?
Cod 2020 baby
came here from NoahJ456 lol
Me too
Really, I just found this for trying to figure out the Zypher cipher :p Anyone have jumbled letters yet?
@@RyanStonedonCanadianGaming Noah has
What if trying to encrypt "red" or "redx" and you get "slk" what does the x pair up with if it is at the very bottom, and same column?
who else is here because of the cold war teasers
Mine, came here from Noah.
How to find inverse if we get the determinant of the key matrix an even number. I think we cant do the same process if we get determinant an even number where we cannot find inverse using this method. Can you do the same problem using key matrix[1 7;9 3].
How is H 7 ...or are we saying A is 0 ...which is a bit confusing
A is 0 yeah so Z will be 25
In the example meet me, why u have taken e as fixed value i.e.., e=3
hi, why exactly are we using Mod ?? what help does mod does??
she sounds like the queen
english accent n dat.
Thank you so much, very helpful.
could anyone explain how to get matriks key at 3:52
Hi, what if u don't know the space is? I mean the chipertext was introduce without space.
Thanks perfect Explained
cryptoniki.blogspot.com/
cryptoniki.blogspot.com/
How do you do the mod 26 calculations?
Ice Fire Just subtract the number by 26 as much as possible. For example, 69 mod 26 is 69-26-26= 17. I hope this helped.
Thanks but what about negative numbers?
The reason we are doing the modulus in the first place is because there are only 26 letters in the English language. The digit 0 represents A. Therefore there are no negative numbers. An example would be -5. We add 26+(-5) to get 21 mod26. I hope this helped!
why we must devide FF at TREFFOREST? when we separete plaintext it looks like TH EM EX ET IN GI SA TX TR EF FO RE ST
How are the matrix dimensions (4*6) chosen?
Matrix dimensions is not important the main thing is to elect the rows after that add your columns as you need.
coming to the decryption part 6:42 , how did she get 12 from 15+23 mod 26? am confused any one care to explain. i will keep re watching to see if i will get it
How do you decide which letter goes first when decoding?