When using same nonce in OCB mode of authenticated encryption, how forgery attack can be done?
The OCB mode of authenticated encryption (used for example with AES) is the fastest way to provide authenticity and confidentiality without having to strive into questions like: Encrypt then MAC, MAC ...
I've just come across this piece of code in Bouncy Castle's implementation of OCB Mode: ...
At the beginning of OCB's white paper [pdf], OCB is compared to other modes, and non-malleability is one of the properties advertised. At the end of the paper, it is mentioned the MAC length can be ...
Assuming the following: Key is randomly generated is being used (32 bytes+) IV is also randomly generated Crypto random key generator is used Data being encrypted contains common bytes like ...