Signature Checksum Service
Generate and verify secure daily signature codes using SHA-256 based checksums
Your Secret PIN
No PIN saved. Enter a 4-digit PIN to get started.
Current Date (IST)
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Generate Today's Code
Generate a unique 4-digit signature code for today using your saved PIN. This code is valid only for the current date.
Your Signature Code for Today
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Verify a Code
Enter the date and signature code to verify. You can verify codes from past dates but not future dates.
Valid Code
The signature code is valid.
How It Works
- Your 4-digit PIN is stored locally in your browser
- The signature code is generated using the current date + your PIN + a server-side secret key
- SHA-256 hash ensures the code cannot be reverse-engineered
- Each day generates a unique code that cannot be backdated
- Verification confirms the code was generated with the correct PIN on the specified date