In this talk I will present an n .log n . 2^{log^*{n}} algorithm
to find the product of two integers which uses modular arithmetic
instead of complex arithmetic. The algorithm is inspired from the
recent breakthrough by Martin Fürer where he gave an algorithm with
similar running time but uses complex arithmetic. Although we gain
nothing in terms of running time, the use of modular arithmetic
makes the algorithm simpler to understand and easier to prove
correctness. However on the negative side the runtime bound depends
on a deep theorem in analytic number theory on the density of primes
in arithmetic progression originaly due to Linnik.
This is joint work with Anindya De, Chandan Saha and Ramprasad
Saptarishi.