RSA Labs has launched a challenge designed to reveal the factors of particular types of large integers. RSA launched a similar Factoring Challenge in 1999, and this latest challenge will reward successful participants with cash prizes up to $200,000 for factoring a 2048-bit number. RSA will reward participants with lesser amounts for successfully factoring numbers with bit lengths that range from 576 bits to 1536 bits.

RSA expects that someone will factor a 576-bit number in the next year or so, but that it will be decades before someone can factor a 2048-bit number. For the challenge, RSA chose the eight particular bit lengths that it uses in devising RSA cryptography systems. RSA will award the prize money to the first person who factors each of the eight challenge numbers.

According to RSA, factoring a number means representing it as the product of prime numbers. Factoring small numbers isn't very difficult; however, as the length of an integer increases, so does the difficulty of finding its prime factors.

In an FAQ published for the challenge, RSA stated that factoring 100-digit numbers is feasible with current technology, but that factoring numbers composed of more than 200-digit numbers is not yet feasible. RSA expects the results of its challenge to help the company determine the state-of-the-art of factoring. RSA also said that the largest number any participant has factored to date contains 512 bits, which took the winning team 7.4 months to complete, from start to finish, during RSA's previous factoring challenge.