Generic Counter Mode implementation in pure Perl. The Counter Mode module constructs a stream cipher from a block cipher or cryptographic hash funtion and returns it as an object. Any block cipher in the Crypt:: class can be used, as long as it supports the blocksize and keysize methods. Any hash function in the Digest:: class can be used, as long as it supports the add method. WWW: https://metacpan.org/release/Crypt-Ctr