I am searching for a secure algorithm to encrypt base62 (or any other base) data for ids in urls.
It should feature:
- No blocksize etc, limiting the length of the message to a factor of n
- If you have the decryted and the encrypted message you should not be able to guess the key
- An avalanche effect
- Any size of charset, not only 256 like in AES, DES etc.
- High performance on modern CPUs
This is not required:
- Streaming, it is only for small data
Is this possible?