A Developer’s Guide to One-Time Passwords (OTPs)

One-time passwords (OTPs) are a common method of adding extra security to application authentication, such as those created by authenticator apps and Yubikeys. OTPs offer an advantage over static passwords in that they are more secure and easier to set up. However, there is a balance to strike between security and user experience when implementing OTPs for applications. OTPs come in three forms: time-synchronized, lockstep synchronized, or transmission-based. They can be delivered by device or app and can either be an addition to the current authentication process or require further authentication factors. While OTPs have benefits such as cutting down on bad security behavior and preventing replay attacks, they also have potential weaknesses like lingering insecurities and annoying user experiences. Developers must carefully consider these factors when implementing OTPs for their applications.