# UW Computational Number Theory and Cryptography Seminar Schedule

## The UW Crypto Seminar Schedule

The seminar meets at 1:30pm on Thursdays in 415L Guggenheim (the Applied Math Building):

### Spring Quarter 2008

April 10, 2008:

April 17, 2008: Reinier Broker -- Modular polynomials for genus 2

Modular polynomials are an important tool in many algorithms involving elliptic curves. In this talk we generalize this concept to the genus 2 case. We give the theoretical framework describing the genus 2 modular polynomials and discuss how to explicitly compute them.

April 24, 2008: Dan Shumow -- Shumow and Schneier Escape from Guantanamo Bay: An adventurous comedy of errors in PRNG cryptanalysis

In the rump session of CRYPTO 2007 I gave a small presentation on a flaw in a recently standardized cryptographic pseudo-random number generation algorithm. Specifically, I pointed out how the designers of the algorithm could have selected constants in a way as to allow them to undermine the security of the algorithm. A few months later Bruce Schneier wrote a blog posting about this result and revealed that the algorithm was actually designed by NSA employees. The story got slashdotted, and pretty soon my name was getting thrown around with some conspiracy theories. In this talk I will give background on Cryptographic PRNGs, and present the details of our result. I will also discuss how Bruce selectively omitted facts from his blog posting in a way to make the NSA (as well as Microsoft) look far worse than they otherwise would.

May 1, 2008:

May 8, 2008:

May 15, 2008: Josh Benaloh -- How Elections Should Really Be Run

This is an election year in the United States, but will votes be properly counted? Once again, there will be extensive press coverage and debates about lost votes, suspicious results, and election technology failures. Every system in widespread use has significant weaknesses and shortcomings. Is there a better way? This talk will describe how to use cryptographic techniques to enable truly verifiable elections. Voters can check that their intended votes are properly recorded, and voters and observers alike can check that all recorded votes are counted accurately. This can be done while preserving secrecy of individual votes and preventing vote selling and coercion. It isn't even terribly difficult, but will it ever be accepted?

Bio: Josh Benaloh is senior cryptographer for Microsoft Research Redmond. He holds an S.B. from MIT and M.S., M.Phil, and Ph.D. degrees from Yale, where his 1987 dissertation was entitled “Verifiable Secret-Ballot Elections.”

May 22, 2008:

May 29, 2008: Peter Montgomery -- Polynomial Selection for the General Number Field Sieve

The Number Field Sieve is asymptotically the fastest algorithm for factoring a large integer N with no small prime factors, such as an RSA modulus. An early step in the algorithm selects two polynomials with a common root modulo N. This talk will present some techniques for choosing the polynomials when N has no nice algebraic form.

June 5, 2008: Robert Miller -- Self-orthogonal error-correcting codes

Error-correcting codes are mathematical structures commonly used in information technology to reduce loss from transmitting data over a channel with noise. I will describe how to generate isomorphism classes of certain types of error-correcting codes, after giving definitions and examples. With time Sloane's construction A, relating binary codes to lattices, will be discussed.

### Fall Quarter 2007

October 10, 2007: Neal Koblitz -- Automated Theorem-Proving -- A Panacea for the Woes of Theoretical Cryptography

October 17, 2007: no talk

October 24, 2007: Robert Bradshaw -- A Mathematician's introduction to Alice and Bob

October 31, 2007: Mike Hansen (joint with the Combinatorics Seminar)

November 7, 2007: Dustin Moody

November 14, 2007: (no seminar -- Sage Days 6)

November 21, 2007:

November 28, 2007:

December 4, 2007: