How secure is PGP?
• The big unknown in any encryption scheme based on RSA is whether or not there is an efficient way to factor huge numbers, or if there is some backdoor algorithm that can break the code without solving the factoring problem. Even if no such algorithm exists, it is still believed that RSA is the weakest link in the PGP chain. Go to Table of Contents • 3.2. Can’t you break PGP by trying all of the possible keys? • This is one of the first questions that people ask when they are first introduced to cryptography. They do not understand the size of the problem. For the IDEA encryption scheme, a 128 bit key is required. Any one of the 2^128 possible combinations would be legal as a key, and only that one key would successfully decrypt all message blocks. Let’s say that you had developed a special purpose chip that could try a billion keys per second. This is FAR beyond anything that could really be developed today. Let’s also say that you could afford to throw a billion such chips at the pr
