1 bit = IDs 1/2 of all results

When you have a sample population to make a random selection from, 1 bit of information is enough to cut that population in half.

2 bits cuts your possibilities in half twice.

3 bits cuts your possibilities in half 3 times.

The general formula for bits of information is:

Where “I” is information, measured in bits, and “p” is the probability of a random selection being identifiable.


Source