Algebra and Cryptography Seminar, Fall 2006

Organizers: Robert Gilman, Alexei Myasnikov, and Vladimir Shpilrain


2:00-3:00 pm
Room 8405, CUNY Graduate Center
365 Fifth Avenue at 34th Street


11:00 am-12:00 pm
Room Peirce 220, Stevens Institute of Technology
Hoboken, NJ

Security seminars at Stevens

September 29, Graduate Center: Vladimir Shpilrain (City College), Public key encryption secure against computationally unbounded adversary
Abstract: In this talk I will show why, contrary to a prevalent opinion, public key encryption can be secure against "encryption emulation" attacks by computationally unbounded adversary, with one reservation: a legitimate party decrypts correctly with probability that can be made arbitrarily close to 1, but not equal to 1.
This is joint work with Denis Osin.

October 6, Graduate Center: Alexander Ushakov (Stevens Institute of Technology), On the length based attack on the Anshel-Anshel-Goldfeld key exchange protocol
Abstract: (1) We show (experimentally) that a carefully designed length based attack can crack a random instance of the multiple conjugacy search problem in braid groups (for certain parameter values), and argue that a completely random choice of public/private information in the Anshel-Anshel-Goldfeld key exchange protocol leads to weak keys.
(2) We Propose a method for key generation resistant against this and several other known attacks.

October 20, Graduate Center: Yesem Kurt (Pomona College), A New Key Exchange Primitive
Abstract: In this talk we will present a new method for key exchange that works over non-commutative groups. The method was developed to overcome the vulnerabilities in the previously proposed schemes, namely Anshel-Anshel-Goldfeld and Diffie-Hellman-like protocols that arise from the linear nature of the relations between the public and private keys. We will discuss the security of the system for a general platform and give a possible setting over braid groups.

November 3, Graduate Center: Delaram Kahrobaei (New York City College of Technology), A Non-Commutative Generalization of El Gamal Key Exchange using Polycyclic Groups
Abstract: In this talk, I will describe a non-commutative key exchange scheme which generalizes the classical El Gamal scheme to polycylic groups. This is joint work with Bilal Khan.

December 8, Graduate Center: Xiaowen Zhang (CUNY Graduate Center), A Chaotic Cipher Mmohocc and Its Randomness Evaluation
Abstract: We briefly introduce a new chaotic stream cipher Mmohocc which utilizes the fundamental chaos characteristics of mixing, unpredictability, and sensitivity to initial conditions. We conducted the randomness statistical tests for the keystreams generated by the cipher. The results showed that the keystreams have successfully passed all the statistical tests of NIST Suite and the Diehard Suite. We conclude that Mmohocc can generate high-quality pseudorandom numbers from a statistical point of view.
This is joint work with Ke Tang (CUNY Graduate Center) and Li Shu (Sichuan University).

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Spring 2006 talks

Fall 2005 talks