# Presentations and Documents for the March 2004 Working Group Meeting

## P1363.1

*Variation in Breaking Times for NTRU and Other Cryptosystems*,
Joseph H. Silverman and William Whyte

LatticeBreakingVariation-1363-2004-03.ppt (Powerpoint)

Comparing average and minimum breaking times for NTRU and other
cryptosystems.

*Lattice Breaking Times*, William Whyte

Lattice-P1363-2004-03.ppt (Powerpoint)

A survey of known results in lattice breaking times, and how to
calculate the breaking times of recommended NTRU lattices.

*Choosing NTRUEncrypt Parameters*, William WHyte

Parameters-1363-2004-03.ppt (Powerpoint)

How to choose NTRUEncrypt parameters. Proposals for slight
variations in NTRUEncrypt encryption schemes to allow for greater
efficiency. NTRUEncrypt schemes that allow for perfect forward
secrecy.

*Cryptography and the Variational Stability of Algorithms*,
Joseph H. Silverman

StabilityOfAlgorithms.pdf
(Acrobat)

Many algorithms exhibit a wide variation of running times when
presented with different inputs. For such algorithms, if the goal is
simply to solve a single problem instance, then it may be more
efficient to set a cutoff time and to start on a new problem
instance if the chosen cutoff time is exceeded. Whether or not this
cutoff strategy is helpful depends on the extent to which the
running time varies. In this note we quantify this notion of
algorithmic variability and we define a stability exponent
`StExp` with the property that a cutoff strategy is useful if
and only if `StExp` > 1. We compute the stability exponent
exactly for exhaustive searches and for meet-in-the-middle (eg,
Pollard rho) searches and we estimate the stability exponent
experimentally for an LLL lattice reduction implementation. These
three examples have applications, respectively, to symmetric ciphers
(DES, AES), elliptic curve cryptosystems (ECC), and lattice
cryptosystems (NTRU).

## P1363.2

*IEEE P1363.2 -- AMP*, Taekyoung Kwan

p1363_200403.ppt (Powerpoint)

A review of the status of the AMP protocol.

*This page was last modified on March 28, 2004.*