How to make a Cypher [Encrypting & Decrypting String]

[Evil_Giraffe]

• Ability to Encrypt & Decrypt String data.

Nowadays, encryption algorithms generally work on bytes, not characters. (Quick, what's the result of ROT13'ing the string 'é'?) You probably (read: definitely) do not want to have your encryption take responsibility for encoding the string data into bytes.

• In order to decrypt the recipient must have the password the first user encrypted with.

If you're doing a search, be aware that this is called 'Symmetric Encryption'. There is also something called 'Asymmetric Encryption' where to decrypt you need a different key to that used to encrypt (obviously, the two keys are mathematically related).