/**
* Sets the AES encryption mode.
*
* WARNING: The strength is deprecated as it has a different effect in MCrypt and OpenSSL. MCrypt was abandoned in
* 2003 before the Rijndael-128 algorithm was officially the Advanced Encryption Standard (AES). MCrypt also offered
* Rijndael-192 and Rijndael-256 algorithms with different block sizes. These are NOT used in AES. OpenSSL, however,
* implements AES correctly. It always uses a 128-bit (16 byte) block. The 192 and 256 bit strengths refer to the
* key size, not the block size. Therefore using different strengths in MCrypt and OpenSSL will result in different
* and incompatible ciphertexts.
*
* TL;DR: Always use $strength = 128!
*
* @param string $mode Choose between CBC (recommended) or ECB
* @param int $strength Bit strength of the key (128, 192 or 256 bits). DEPRECATED. READ NOTES ABOVE.
*
* @return mixed
*/
public function setEncryptionMode($mode = 'cbc', $strength = 128);