# Is there any correlation in between two AES with a key differ only by one bit? (ECB mode)

Given two AES (128bit, ECB mode) with almost equal keys $$k_1,k_2$$: 127 of the 128 key bits are equal. Is there any correlation in between the ciphers they build?

$$AES_1(m_i) = c_i$$ $$AES_2(m_i) = d_i$$

Would it be different to two keys differ by 64bit? by 128bit? Or the same key but shifted by $$n$$ bit?

E.g. An adversary found some correlation in between the target AES mapping and another he knows the key of. Does this help him anything for deriving the key of the target AES?

• The key owner can somehow be persuaded to compute three other keys $$K_B$$, $$K_C$$ and $$K_D$$, from $$K_A$$, using a specific derivation algorithm ($$K_B$$ is equal to $$K_A$$ XORed with a constant that the attacker chooses; $$K_C$$ and $$K_D$$ use a more complex but equally deterministic derivation algorithm).