Which of the following statements are TRUE about encryption techniques?

A. In symmetric key cryptography, the secrecy/protection of the key generating function must be of higher level than the decrypting function.

B. The DES technique works by taking 64-bit chunk value and 56-bit key over a series of transformations.

C. The Twofish symmetric block algorithm works on variable key length of up to 196 bits over a block of 128 bits.

D. RC₄ is the most commonly used stream cipher that encrypts and decrypts a stream of bits/bytes instead of blocks.