Unknown key-share attack

As defined by Blake-Wilson & Menezes (1999), an unknown key-share (UKS) attack on an authenticated key agreement (AK) or authenticated key agreement with key confirmation (AKC) protocol is an attack whereby an entity $A$ ends up believing she shares a key with $B$, and although this is in fact the case, $B$ mistakenly believes the key is instead shared with an entity $E \neq A$.

References

• Blake-Wilson, S.; Menezes, A. (1999), "Unknown Key-Share Attacks on the Station-to-Station (STS) Protocol", Public Key Cryptography (PDF), Lecture Notes in Computer Science 1560, Springer, pp. 154–170