RSA is a "public key" cryptography system, where you have a public key that everyone's allowed to know, and a private key that you keep secret. Anyone can use t

RSA is a "public key" cryptography system, where you have a public key that everyone's allowed to know, and a private key that you keep secret. Anyone can use the public key to encrypt messages, but you need the private key to decrypt messages. (You can also use it for digital signatures, where you provide a copy of the message and also "encrypt" the message with the private key; anyone can publicly decrypt it. If the "decrypted" message matches the original, then the signature proves that the message was signed by someone who has the private key.) RSA works by starting with two large random prime numbers P and Q. You multiply P and Q to get a number M, and that number becomes part of the public key. An attacker who knows P and Q can compute your private key and decrypt your messages. RSA assumes that it's computationally infeasible to factor M back into P and Q. It's supposed to be something like O(2^n), where n is the length of M. A fast factorization algorithm breaks that assumption, allowing attackers to decrypt messages and forge digital signatures. If Schorr has found an algorithm that does this, I would say it "destroyes the RSA cryptosystem." (My guess: it probably doesn't work, because drafts of this paper have been out for a few years and the sky hasn't fallen yet.)