Blowfish

Blowfish is a symmetric block cipher used in many encryption products. Due to its variable key length of 32-448 bits, this algorithm is very secure.
This is an algorithm created in response to the old DES. It uses 64-bit blocks in its encryption and 16 "rounds" of the Feistel function.
The only disadvantage is the advantage of a variable encryption key - every change slows down the process.