4 ms·
I don't know about this feature, but why couldn't it be stored as a hash?
by bradjohnson 10y ago
I don't know about this feature, but why couldn't it be stored as a hash?
- Scirra_Tom 10y agoI might be an order of magnitude off here, but I believe there's only around 1 billion unique numbers per card once you take away check sum digits and look at how they are issued. Assuming that's correct, it really wouldn't take up much memory or computing power to create a lookup table for every credit card number with hash x.