The RSA Factoring Challenge was a series of cryptographic challenges launched by RSA Security to encourage the development of more efficient factoring algorithms. It played a significant role in advancing the state of the art in factoring algorithms.
The challenges involved factoring RSA-modulus numbers of increasing size. The first challenge, launched in 1991, involved a 129-digit number, and subsequent challenges involved larger and larger numbers. The final challenge, launched in 2007, involved a 2048-bit RSA number with a value of RSA-200.
The RSA Factoring Challenge lasted for over a decade and generated a lot of interest and progress in the field of cryptography. The challenge played a significant role in advancing the state of the art in factoring algorithms and contributed to the development of new methods for breaking cryptographic schemes based on the difficulty of factoring large numbers.
Several teams successfully factored the RSA numbers involved in the challenge, including the first challenge which was factored in 1994 by a team led by Arjen K. Lenstra. The second challenge was factored in 1999 by a group led by Lenstra and Mark Manasse.
Despite the success of the earlier challenges, the final challenge remained unbroken until it was declared officially closed in 2010. The challenge offered a cash prize of $200,000 to the first team to factor the number, but no team was able to claim the prize.
The RSA Factoring Challenge represents a significant chapter in the history of cryptography and is still studied and referenced by researchers and students today.