A Framework for the Design of Good Watermark Identification Codes

Pierre Moulin and Ralf Koetter

The fundamental difference between the data-hiding and watermark signature
verification problems was highlighted in a 2001 paper by Steinberg and
Merhav. In data hiding, the maximum number of messages that can be
reliably decoded is essentially $2^{nC}$, where $n$ is
the host sequence length and $C$ is the data-hiding capacity.
A dramatically different result is obtained for signature verification:
in principle one can discriminate between a doubly exponential
number of signatures: $2^{2^{nC'}}$, where $C'$ is the identification
capacity. This paper proposes a practical design of codes for the latter 
application and compares the results with current designs in the literature.