# Mathematical Digest

### Short Summaries of Articles about Mathematics

in the Popular Press

"Crunching Internet Security," by Ivars Peterson. *Science News,* 2October 1999, page 221.

Can internet security codes be broken? One widely used scheme for encryptinginformation transmitted over the internet is based upon the principle that verylarge numbers are difficult to factor. The scheme, called RSA, requiresknowing the factors of a 155 digit number in order to unscramble theinformation. Factoring such a large number is so time consuming it isconsidered impossible in the practical world, and the information is consideredsafe from hackers. This article explains that mathematicians in Amsterdamrecently succeed in factoring such a number, however. Although it took 5months on 300 PCs and one supercomputer, there is concern that with the growingspeed of computers it may become even more feasible in the future, andencryption schemes will have to begin using even larger numbers.

*--- Elizabeth Moisan*