Stream.arcfourThe ARCfour (``alleged RC4'') stream cipher. The argument is the key, and must be of length 1 to 256. This stream cipher works by xor-ing the input with the output of a key-dependent pseudo random number generator. Thus, decryption is the same function as encryption.
transform src spos dst dpos len encrypts or decrypts len characters, read from byte array src starting at position spos. The resulting len characters are stored in byte array dst starting at position dpos.