Generate Verification Code (TOTP algorithm) without saving database

The method used to do validation is new Random (). Next (10000,99999) generate random number of users in the database after the user table, the user entered the verification code to query the user table to do comparisons, netizens said this approach is too low B, should use TOTP algorithm to get, at the same time give a URL to come over, https:// Github.com/arch/standard/blob/master/src/arch.standard/utils/totp.cs

Went up to see the next, do not understand, but should still be used, I tried it, you can use, good good, support support ...

Code has joined its own brisket common class library, git address: https://coding.net/u/niunan/p/niunan_utility/git