Moritz Höppner (@moritzhoeppner)

Cryptography Truncation Issues: Padding And Block Structure Challenges

5m

When a ciphertext is truncated, use `openssl` with `-d` option & specify IV & key to decrypt. Alternatively, keep last 2 blocks of original ciphertext or remove garbage blocks using `dd`.

Bitflip Attack On AES-CBC Encryption

Moritz Höppner @moritzhoeppner

6m

Bitflip attack on AES-CBC: change IV to alter decryption outcome. XOR original plaintext with desired output to generate new IV, then decrypt ciphertext with new IV.

Tampering With Encrypted Files: A CBC Mode Vulnerability

Moritz Höppner @moritzhoeppner

6m

Tamper encrypted HTML file using CBC encryption: Replace `<html>` in 2nd block with `:)` by modifying 1st ciphertext block & decrypting with OpenSSL.