public function toBinary($hashAlgo)
	{
		$s = self::SIGNATURE1 . self::SIGNATURE2 . self::VERSION
			. self::fieldToString(2, $this->cipher)
			. self::fieldToString(3,
			$this->compression == self::COMPRESSION_GZIP
				? self::INT_1 : self::INT_0)
			. self::fieldToString(4, $this->masterSeed)
			. self::fieldToString(5, $this->transformSeed)
			. self::fieldToString(6, $this->rounds)
			. self::fieldToString(7, $this->encryptionIV)
			. self::fieldToString(8, $this->randomStreamKey)
			. self::fieldToString(9, $this->startBytes)
			. self::fieldToString(10,
			$this->randomStream == self::RANDOMSTREAM_SALSA20
				? self::INT_2 : self::INT_0)
			. self::fieldToString(0, null);
		$this->headerHash = hash($hashAlgo, $s, true);
		return $s;
	}