## CryptoDB

### Yongdong Wu

#### Publications

Year
Venue
Title
2008
EPRINT
This paper investigates the security of FTT (fully collusion resistant traitor tracing) schemes in terms of DOT (Denial Of Tracing) and framing. With DOT attack, a decoder is able to detect tracing activity, and then prolongs the tracing process such that the tracer is unable to complete tracing job in a realistic time duration and hence has to abort his effort. On the other hand, by merely embedding several bytes of non-volatile memory in the decoder, we demonstrate, for the FTT schemes, how the decoder can frame innocent users at will. Furthermore, we propose a countermeasure on the framing attack.
2001
EPRINT
In Crypto'99, Boneh and Franklin proposed a public key traitor tracing scheme~\cite{Boneh}, which was believed to be able to catch all traitors while not accusing any innocent users (i.e., full-tracing and error-free). Assuming that Decision Diffie-Hellman problem is unsolvable in $G_{q}$, Boneh and Franklin proved that a decoder cannot distinguish valid ciphertexts from invalid ones that are used for tracing. However, our novel pirate decoder $P_{3}$ manages to make some invalid ciphertexts distinguishable without violating their assumption, and it can also frame innocent users to fool the tracer. Neither the single-key nor arbitrary pirate tracing algorithm presented in~\cite{Boneh} can identify all keys used by $P_{3}$ as claimed. Instead, it is possible for both algorithms to catch none of the traitors. We believe that the construction of our novel pirate also demonstrates a simple way to defeat some other black-box traitor tracing schemes in general.

#### Coauthors

Robert H. Deng (1)
Jeff Jianxin Yan (1)