> Creating obfuscated values using integers

While that is often neat solution, do not do that by simply XORing the numbers with constant. Use a block cipher in ECB mode (If you want the ID to be short then something like NSA's Speck comes handy here as it can be instantiated with 32 or 48 bit block).

And do not even think about using RC4 for that (I've seen that multiple times), because that is completely equivalent to XORing with constant.