How safe is encryption using digital certificates (SSL)?
Digital certificates uses public key encryption to exchange a session key between the client and server; this session key is used to encrypt the http transaction (both request and response). Each transaction uses a different session key so that if someone manages to decrypt a transaction, that does not mean that they have found the server’s secret key. If they want to decrypt another transaction, they will need to spend as much time and effort on the second transaction as they did on the first. Qwest digital certificates provide encryption using a 128 bit encryption. To crack 512 bit encryption, there are 2128 possible keys. To crack a message encrypted with such a key by brute force would take significantly longer than the age of the universe using conventional technology.
