title: How to encrypt or decrypt with Rijndael and a block-size of 256 bits?
body: <p>For certain reasons I need to implement Rijndael de/compression with a blocksize of 256 bits instead of AES which uses a block size of 128 bits (reason: data is encrypted in PHP using Rijndael...).</p>
  
  <p>How can I change the block-size for a cipher?</p>
  
  <p>If i just get a cipher with <code>"RIJNDAEL/CFB/PKCS5Padding"</code> and try to initialize a IV with 256 bits I get an exception, because the block-size is only 128 bits.</p>