The General Number Field Sieve (GNFS) is the fastest known method for factoring "large" integers, where large is generally taken to mean over 110 digits. This makes it the best algorithm for attempting to unscramble keys in the RSA [2, Chapter 4] public-key cryptography system, one of the most prevalent methods for transmitting and receiving secret data. In fact, GNFS was used recently to factor a 130-digit "challenge" number published by RSA, the largest number of cryptographic significance ever factored.