Definition of Short Authentication String I am studying for my cryptography final and I passed by the following term: short authentication string. Please, can anyone explain it to me, thank you very much.
The Short Authentication String (SAS) is used in various protocols, but in short, SAS is produced to transfer a long authentication tag into a smaller so that the two users can verbally verify. For example;

In Diffie-Hellman key Exchange, there is always a risk of Man-in-the-Middle attack. To ensure that there is no attacker in the first session, that there are no shared secrets yet, a SAS can be used. After verbal communication, if the values don't match then Man-in-the-Middle attack is detected.

Some Protocols that uses SAS;


ZRTP: Media Path Key Agreement for Unicast Secure RTP
Short Authentication Strings for TLS
Device Pairing Using Short Authentication Strings