general md5 hashing question ... not CI specific

[eluser]davidbehler[/eluser]
In theory it's possible that there is more than 1 value that create the same hash when using md5. But the chances are pretty slim so there shouldn't be much of a problem if you use md5 for creating your unique value.
Before inserting an entry you could check if there already is an entry with that id and if so just create a new hash by adding a random number to your original value for example.