code: public void init(byte[] IV, byte[] key){
  		if(IV.length != blockSize || key.length != blockSize)
  			throw new RuntimeException("key and IV need to be same as block size (" + blockSize + ")."); //TODO subclass exception
  		this.key = key;
  		this.IV = IV;
  		prehash = Misc.cleanXOR(IV, key);
  		cfg = true;
  		blockNo = 0;
  		buffer = new byte[blockSize];
  		bufferIndex = 0;
  	}
docs: Initializes the cipher with key and IV
  @param IV A 256 bit initialization vector to use for the cipher.
  @param key A 256 bit key to encrypt with.