!!! !!! !!! !!! !!! !!! !!! !!! !!! !!! !!! !!! !!! !!! !!! !!! !!! !!! !!! !!!
-------------------------------------------------------------------------------
                                       
                                       
                   B O S T O N   U N I V E R S I T Y
                                       
                      Computer Science Department
                                       
                          C O L L O Q U I U M


            Cryptography: Beyond Ink and Paper Metaphors 

                              Ari Juels

	    	           RSA Laboratories 

 			   Friday, April 30 
                                       
                                11:00am
                       (Coffee served at 10:45am)

                                       
                         Seminar Room / MCS 135
                                       

-------------------------------------------------------------------------------


    The field of cryptography has reached a critical point of maturation. It is
    capable of translating into the digital world most of the mechanisms for
    privacy and authenticity that are important in the physical world. Basic
    building blocks like digital signatures and public key encryption algorithms
    are well tested and widely trusted, effectively mimicking and enhancing the
    functionality of handwritten signatures and sealed envelopes. A new phase of
    innovation in cryptography promises to deliver even more: practical
    algorithms that go beyond metaphorical comparisons with ink and paper. 

    In this talk, we shall discuss two such algorithms. The first relates to
    biometrics, that is, identification of computer users based on unique
    biological characteristics. Conventional hash functions have been used for
    many years to protect passwords in UNIX systems. Biometric data, an
    alternative or supplement to traditional passwords, cannot benefit from such
    protection, because biometric measurement is approximate in nature. We
    demonstrate a primitive, known as a fuzzy hash function, that confers on
    biometric data essentially the same security guarantees that a conventional
    hash function brings to passwords.

    The second algorithm relates to the millionaires' problem. This is the task
    of enabling two millionaires to hold a conversation in which they learn who
    has more money, but, remarkably, gain no additional information. General
    cryptographic techniques known as secure multiparty computation offer a
    solution to the millionaires' problem and a host of related problems. We
    describe a new approach to secure multiparty computation that holds the
    promise of greater efficiency, simplicity, and flexibility than previous
    approaches. In consequence of this and related results, we believe that
    sealed-bid auctions without trusted auctioneers may soon be practically
    realizable.

    This talk assumes only minimal background in cryptography.

    Host: John Byers (byers@cs.bu.edu)

-------------------------------------------------------------------------------
For colloquium info, including directions, see http://cs-www.bu.edu/colloquium
-------------------------------------------------------------------------------