Security heard “otp” and forced us through a 2 month security/architecture review process for this sign-off feature that we built with COTs libraries in a single sprint.
We pushed back and initially they agreed with us and gave us an exception, but about a year later some compliance audit told them it was no longer acceptable and we had to change it ASAP. About a year after that they told us it needed to be ten characters alphanumeric and we did a find and replace in the code base for "verification code" and "otp" and called them verification strings, and security went away.