Discrete time window calculation example

  • Published on Feb 10, 2026
  • 1 minute(s) read
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Initial parameters

  • Digipass time step: 36 seconds

  • Identification time window: 10 Digipass time steps

  • Discrete synchronization time window: 3 hours (SyncWindow = 3 | SW_DISCRETE)

Step 1: Mobile Authenticator Studio is correctly adjusted

 

Figure: Discrete time window example – Step 1

An authentication request succeeds because:

  • The SyncWindow is configured to accept OTPs from GMT-1 to GMT+1 (SyncWindow = 3 | SW_DISCRETE).

  • The mobile phone drift is less than ITimeWindow x time step/2.

The authentication request iterates on:

  • Discrete time window GMT+0 (iteration 1): OTP validated.

Step 2: After the daylight savings adjustment, the mobile phone clock is set back one hour

 

Figure: Discrete time window example – Step 2

An authentication request succeeds because:

  • SyncWindow is configured to accept OTPs from GMT-1 to GMT+1 (SyncWindow = 3 | SW_DISCRETE).

  • The mobile phone drift is less than ITimeWindow x time step/2.

The authentication request iterates on:

  • Discrete time window GMT+0 (iteration 1)

  • Discrete time window GMT-1 (iteration 2)

  • Discrete time window GMT+1 (iteration 3): OTP validated

After successful authentication at GMT+1, the SyncWindow stays centered around GMT+0.

Step 3: The mobile phone is now set 2 hours later

 

Figure: Discrete time window example – Step 1

An authentication request succeeds because:

  • SyncWindow is configured to accept OTPs from GMT-1 to GMT+1 (SyncWindow = 3 | SW_DISCRETE).

  • The mobile phone drift is less than ITimeWindow x time step/2.

The authentication request iterates on:

  • Discrete time window GMT+1 (iteration 1)

  • Discrete time window GMT+0 (iteration 2)

  • Discrete time window GMT-1 (iteration 3): OTP validated

The first iteration starts at the previous time zone (here GMT+1).