Signature amortization schemes have been introduced
for authenticating multicast streams, in which, a single signature is amortized over several packets. The hash value of each packet is
computed, some hash values are appended to other packets, forming what is known as hash chain. These schemes divide the stream into
blocks, each block is a number of packets, the signature packet in these schemes is either the first or the last packet of the block.
Amortization schemes are efficient solutions in terms of computation and communication overhead, specially in real-time environment.
The main effective factor of amortization schemes is it?s hash chain construction. Some studies show that signing the first packet of each
block reduces the receiver?s delay and prevents DoS attacks, other studies show that signing the last packet reduces the sender?s delay.
To our knowledge, there is no studies that show which is better, to sign the first or the last packet in terms of authentication probability
and resistance to packet loss.
In this paper we will introduce another scheme for authenticating multicast streams that is robust against packet loss, reduces the overhead, and prevents the DoS attacks experienced by the receiver in the same time. Our scheme-The Multiple Connected Chain signing
the First packet (MCF) is to append the hash values of specific packets to other packets, then append some hashes to the signature
packet which is sent as the first packet in the block. This scheme is especially efficient in terms of receiver?s delay. We discuss and evaluate the performance of our proposed scheme against those that sign the last packet of the block.