One Time Pad
I did a little bit of research on One Time Pads (OTP). I guess from a theoretical standpoint, they are absolutely secure, but I don’t think it’s very realistic. The problem is the assumptions they make are unrealistic:
* The key must be 100% purely random
* The key must be transmitted securely (!!!)
* The key or any portion of the key can only be used once
* The key must be the same length as the message.
If you achieve these, then you have a pretty cool method of encryption which cannot be cracked even with infinite computing power.
But I have a particular issue the second point. In order to ensure the security of the message, you have to ensure the security of the decryption key (which happens to be symmetric).
In other words: the algorithm is only really as secure as the method you use to transmit the key. So there really is no difference in security between sending the message along the same lines that you have sent the key, and save yourself the trouble of encrypting or decrypting.
http://en.wikipedia.org/wiki/One_time_pad
