Generating a non-guid unique key outside of a database
<p>I have a situation where I need to create some kind of uniqueness between 'entities', but it is not a GUID, and it is not saved in a database (It is saved, however. Just not by a database).</p>

<p>The basic use of the key is a mere redundancy check. It does not have to be as scalable as a real 'primary key', but in the simplest terms I can think of , this is how it works.</p>

<p><code>[receiver]</code> has <code>List&lt;possibilities&gt;</code>.</p>

<p><code>possibilities</code> exist independently, but many will have the same values (impossible to predict. This is by design)</p>

<p>Frequently, the <strong>receivers</strong> list of <code>possibilities</code> will have to be emptied and then refilled (this is a business requirement).</p>

<p>The key is basically used to add a very lightweight redundancy check. In other words, sometimes the same possibility will be repeated, sometimes it should only appear once in the receiver's list. </p>

<p>I basically want to use something very light and simple. A string is sufficient. I was just wanting to figure out a modest algorithm to accomplish this. I thought about using the <code>GetHashCode()</code> method, but I am not certain about how reliable that is. Can I get some thoughts?</p>
