On the security of a public-key traitor tracing scheme with sublinear ciphertext size

摘要

Traitor tracing refers to a class of encryption schemes that can be used to deter key-leakage. They apply to a setting that involves many receivers, each one receiving a fingerprinted decryption key. If a set of malicious receivers (also known as traitors) constructs an illicit decoder then a tracing mechanism enables an authority to identify at least one of the traitors. The very first traitor tracing scheme that has sublinear ciphertext size and is capable of tracing unambiguously illicit decoders that may shut-down (or employ some sort of self-defensive mechanism that would be adverse to tracing) was proposed in AsiaCrypt 2004 by Matsushita and Imai.