Non-Degrading Erasure-Tolerant Information Authentication With an Application to Multicast Stream Authentication Over Lossy Channels

The concept of erasure-tolerant information authentication was recently introduced to study an unconditionally secure setting where it is allowed to lose a limited number of message letters during transmission. Even if a part of the message is lost, the verifier will still be able to check the authenticity of some or all of the received message letters. In general, there might be some letters whose authenticity cannot be verified although they have arrived at the recipient's side. These letters will be discarded. The authors consider a special case when the verifier can always check the authenticity of all received message letters.