| Option | Description |
| Field | Description |
| Time-based one-time passwords (TOTP) for web authentication | Select Enable. |
| Allow emergency scratch codes | Select Yes (default) to allow users to provide one of ten scratch codes rather than a TOTP token. This option is useful for allowing users to log in if their TOTP application is unavailable, for example, if they lose a device that runs it.
Users are shown the scratch codes right after they set up TOTP successfully. After a scratch code is used, it can't be used again. |
| Email scratch codes to a user | If you allow emergency scratch codes, selectYes to send an encrypted email containing the scratch codes to a user when they initially set up TOTP or if their configuration is reset and they set it up again. Users also copy the scratch codes right during setup. |
| Maximum number of secrets | The number of TOTP URIs (accounts) that each user can set up to access a Domino server: 1, 2, or 3 (default). More than one TOTP URI might be useful if the TOTP application runs on multiple devices. |
| Algorithm | The algorithm used to generate the token. Use the default,HMAC-SHA256, unless you find that there are older TOTP applications in your environment that don't support it.
Note: The ID vault server supports downgrading the HMAC algorithm by one level, for example, from HMAC-SHA256 to HMAC-SHA1. Therefore, we have kept the default algorithm as HMAC-SHA256 to support TOTP clients like Google Authenticator. Authy and Microsoft Authenticator support HMAC-SHA1 currently and they work against the server enabled for either HMAC-SHA1 or HMAC-SHA256. |