Difference between revisions of "Cryptography Tricks"

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(AES-ECB tricks)
(AES-CTR tricks)
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* Recovery of partial plaintext with two ciphertexts encrypted with same key and iv by knowing where zeroes (\x00) are located
 
* Recovery of partial plaintext with two ciphertexts encrypted with same key and iv by knowing where zeroes (\x00) are located
 
* This trick was used in the recovery of the ebootrom keys
 
* This trick was used in the recovery of the ebootrom keys
 +
* Xoring these ciphertexts will reveal plaintext where in both locations there are zeroes in one place and plaintext in the other
  
 
= AES-CBC tricks =
 
= AES-CBC tricks =

Revision as of 00:00, 20 August 2021

Here are some cryptography tricks that i've learned with some important people and that helped made this page. They helped a lot with the Keys and Seeds page construction. Use them wisely :)

AES-CTR tricks

  • Recovery of partial plaintext with two ciphertexts encrypted with same key and iv by knowing where zeroes (\x00) are located
  • This trick was used in the recovery of the ebootrom keys
  • Xoring these ciphertexts will reveal plaintext where in both locations there are zeroes in one place and plaintext in the other

AES-CBC tricks

  • The iv of a CBC operation is always the previous 0x10 block, UNLESS it's the starting operation. in this case it is specified by the end-user

AES-ECB tricks

  • If cbc is used on a block and if the attacker knows where 16 bytes of zeroes are located in known plaintext with given ciphertext location, he can use AES-ECB with the guessed key on that location. if there is a match of the previous 16 bytes as result, the attacker automatically knows the guessed key is the correct key