生成唯一的密钥以识别系统

Question

I need to generate a unique identifier based on some information. There will be multiple clients and one server. Each client will call a web service at server for the first time registration. Each client will send system name (considered to be unique), logged in user name, date of registration, mac-address (probable) etc.

Based on this information, I want to generate a unique identifier for that particular user. My Server is written in PHP. I know some hash methods can generate some unique key, but what is the standard and what is being used generally?

Thanks for help.

Answer 1

An effective approach to this is to add a salt (a few characters known only to the server) to the concatenated details from the clients. Take a hash of that data. In the example below, the salt is mysalt.

<?php
echo hash('ripemd160', 'mysalt' . clientHostname . clientUsername . clientRegistrationDate);
?>

This approach means that the hash can't easily be guessed/reverse-engineered by a third party.