src/Pdf/Protection.php
public function objectKey($n)
	{
		if ($this->useRC128Encryption) {
			$len = 16;
		} else {
			$len = 10;
		}

		return substr($this->md5toBinary($this->encryptionKey . pack('VXxx', $n)), 0, $len);
	}
public function objectKey($n)
	{
		if ($this->useRC128Encryption) {
			$len = 16;
		} else {
			$len = 10;
		}

		return substr($this->md5toBinary($this->encryptionKey . pack('VXxx', $n)), 0, $len);
	}
public function objectKey ( $ n ) { if ( $ this -> useRC128Encryption ) { $ len = 16 ; } else { $ len = 10 ; } return substr ( $ this -> md5toBinary ( $ this -> encryptionKey . pack ( 'VXxx' , $ n ) ) , 0 , $ len ) ; }
Compute key depending on object number where the encrypted data is stored

@param int $n

@return string
Compute key depending on object number where the encrypted data is stored