# Fully Collusion Resistant Traitor Tracing With Short Ciphertexts and Private Keys

**Authors:**

*D. Boneh, A. Sahai, and B. Waters*

** Abstract: **

We construct a fully collusion resistant tracing traitors
system with sublinear size ciphertexts and constant size private keys.
More precisely, let N be the total number of users. Our system
generates ciphertexts of size O(sqrt(N)) and private keys of size
O(1). We first introduce a simpler primitive
we call *private linear broadcast encryption* (PLBE) and show
that any PLBE gives a tracing traitors system with the same
parameters. We then show how to build a PLBE system with
O(sqrt(N)) size ciphertexts. Our system uses
bilinear maps in groups of composite order.

** Reference:**

In proceedings of Eurocrypt '06, LNCS 4004, 2006, pp. 573-592

**Full paper:**
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