Coding Theorems on the Simple Capacity for Digital Fingerprinting Codes
Digital fingerprinting codes provide a method to protect licensed digital
contents against illegal redistribution. We focus on the situation where
two malicious users collude and generate an overwritten codeword by using
a memoryless collusion channel. We investigate coding theorems
for the digital fingerprinting codes using a simple decoder
such that each user is judged as malicious or innocent
from an overwritten codeword together with his/her codeword.
We first discuss the case where the collusion channel is known.
We give a formula of the simple capacity.
Next, we consider the case where the collusion channel is unknown.
We succeed in giving the formula of a simple capacity of
this case as well.