TIM DIETRICH OF FMAUTHENTICATOR (and FileMaker Addict, among others) offers two factor authentication through FileMaker:
FMAuthenticator is a technique for implementing two-factor authentication (2FA) in the FileMaker database platform.
What is Two-factor Authentication?
Two-factor authentication requires users to provide two forms of identification before being granted access to a system. The two forms of identification are often described as being "something the user knows" (their username and password) and "something the user has" (such as their cell phone).
How does FMAuthenticator work?
1. A user logs into a FileMaker database as they normally would (by providing their account name and password).
2. FileMaker generates a random security code, and sends it as a text message to the user's mobile device.
3. FileMaker asks the user to enter the code.
4. If the code is entered correctly, then the user is allowed to access the database.
The best part: It free! Don't wait, get over there now and download it right away.