These are two sample names of keys:
Key nº 2816371
Key nº 2802409
Not very easy to remember, aren't they. If you need to know which one is which one and you don't carry around a dangerous key id's list, then you are out of luck.
My suggestion is to translate on the fly the last four numbers to letters. Lets say we got these two sets. A and K are zero:
ABCDEFGHIJ
KLMNOPQRST
To display the last four digits, the code picks a letter from one, then a letter from the other, and the examples would look like:
Key 281GNHL
Key 280CNAT
I know there are papers listing key numbers, but it doesn't need a degree of cryptography to translate back from the new names.

