From 7872bbcaf421bbb2fd3ab5fb1283e9cb8282a02f Mon Sep 17 00:00:00 2001
From: cyfraeviolae
Nonce reuse. Due to rising entropy
- prices, Roseacrucis has started to reuse nonces. You must perform the
+ prices, Roseacrucis has started to reuse AES-GCM nonces. You must perform the
Forbidden Attack in order to recover the authentication key and
forge arbitrary ciphertext.
- We plug \(h\) back into the first equation to recover \(s\), - and finally, we can forge the MAC for arbitary ciphertext under the - same nonce. Note that there may be multiple possible monomial roots; - in this case, one can check each possibility online. + We plug \(h\) back into the first equation to recover \(s\), and we + can forge the MAC for arbitary ciphertext under the same nonce. + Note that there may be multiple possible monomial roots; in this + case, one can check each possibility against the enemy. +
++ Readers who wish to implement this attack themselves can try + Cryptopals; specifically + Set 8 Problem 62.