CBC MAC for Real-Time Data Sources.
Erez Petrank, Charles Rackoff · 1997
The Cipher Block Chaining (CBC) Message Authentication Code (MAC) is an authentication method which is widely used in practice. It is well known that the naive use of CBC MAC for variable length messages is not secure, and a few thumb rules for the correct use of CBC MAC are known by "folklore". The first rigorous proof of the security of CBC MAC, when used on fixed length messages, was given only recently by Bellare, Kilian and Rogaway [3]. They also suggested variants of CBC MAC that handle variable length messages but in these variants the length of the message has to be known in advance (i.e., before the message is processed). We study CBC authentication of real time applications in which the length of the message is not known until the message ends, and furthermore, since the application is real-time, it is not possible to start processing the authentication only after the message ends. Providing authentication for real time communication is an important task, which involves authe...