Online mode

One-time passwords and digital signatures are presented to the host in the order they were generated.

Three OTPs are generated with the events e=1, e= 2, and e=3. The OTP generated with e=2 has to be submitted before the one with e=3. Presenting the OTP generated with e=1 after the one generated with e=3 would cause an authentication failure.

In this mode, the lower window boundary is:

Lower boundary = Current event value + 1

The upper window boundary is:

Upper boundary = Current event value + window event

Authentication Suite Server SDK will consider all OTPs with a value that is within these boundaries as valid. After a successful validation, the event value in the authenticator application BLOB is updated with the authenticator application event value used to generate the OTP.

One-time passwords are always validated in online mode. Signatures are only validated in online mode if the OnlineSG kernel parameter is equal to 1 or 2. Signature validation in online mode is recommended in most cases.