On perfect traitor tracing

Abstract

We analyze the perfect security aspects of traitor tracing and show that perfect fairness (an innocent party is never accused) is impossible, except if the pirate key allows full decryptability or if nobody is ever accused. Similarly, perfect accusability (at least one traitor is always correctly accused) is impossible, except if the pirate key allows full decryptability or some innocent people will always be among the accused. We also show possibility results.