On the Security of a Repaired Mental Poker Protocol

12 years 3 months ago
On the Security of a Repaired Mental Poker Protocol
In 2003, Zhao, Varadharajan and Mu proposed a mental poker protocol whose security was shown to be flawed in 2004: any player (or any outsider knowing the deck coding) is able to decrypt encrypted cards without knowing the encryption key. In 2005, the first two authors published a repaired version of this TTP-free mental poker protocol. We show here that this second version is also flawed: the first player can find all cleartexts of the final encrypted shuffled deck of cards. Both protocols are similar to Shamir-Rivest-Adleman’s mental poker, but they replace an exponential commutative cipher with an ElGamal-like commutative cipher. We conclude that changing the underlying commutative cipher is the reason of their weakness.
Jordi Castellà-Roca, Josep Domingo-Ferrer,
Added 12 Jun 2010
Updated 12 Jun 2010
Type Conference
Year 2006
Where ITNG
Authors Jordi Castellà-Roca, Josep Domingo-Ferrer, Francesc Sebé
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