mcrypt_enc_is_block_algorithm
    (PHP 4 >= 4.0.2, PHP 5)
mcrypt_enc_is_block_algorithm -- Checks whether the algorithm of the opened mode is a block algorithm
Description
bool 
mcrypt_enc_is_block_algorithm ( resource td )
     This function returns TRUE if the algorithm is a block algorithm,
     or FALSE if it is a stream algorithm.