Originally posted by headkaze
I need a function that does the following:

1. Takes a 10 digit number as input and creates a unique hash of that number
3. The algorithm should be one-way (ie. irreversable)
These two points appear to be at odds - at least in my opinion.

Unique means that there is only "one" new pattern for every "original" values.

One-way means that many different "original" values become the same "new" pattern. That is how "one-way" is implemented - by having many "originals" flow into a single "new" pattern. That makes it impossible to reverse...