4 ms·
> it does seem like the one time pad could encrypt the entire message simply by using some clever way of "extending" the key Any way of meaningfully extending
by mseebach 9y ago
> it does seem like the one time pad could encrypt the entire message simply by using some clever way of "extending" the key
Any way of meaningfully extending the key will be vulnerable to a kind of analysis well understood 70 years ago.
This is basically what almost the entire field of cryptography is about: Figure out how you can effectively and securely encrypt things with a key that's a lot shorter than your cleartext.
- Someone 9y agoIndeed. The two simplest examples are the Caesar cipher (https://learncryptography.com/classical-encryption/caesar-cipher https://learncryptography.com/classical-encryption/caesar-ci..., key length of 1 character) and the Vigenère Cipher (https://learncryptography.com/classical-encryption/vigenere-cipher https://learncryptography.com/classical-encryption/vigenere-..., key length as long as you want it to be) Both extend the key by repeating it. That is not a good idea.