Step 5 of 7
Cryptographic Signature
Customer signs the instruction with their passkey for non-repudiation
Instruction Summary
Review Your Instruction
Customer Name:
Sarah Mitchell
Matter Reference:
REF-9F2A-47B1
Instruction Type:
Bank Account Details
Bank Name:
Barclays Bank
Sort Code:
20-00-00
Account Number:
12345678
Account Holder:
Sarah Mitchell
Timestamp:
9 Dec 2025, 14:32 GMT
shepwedd.com is requesting authentication
Confirm this action with your passkey
Touch ID / Face ID / Windows Hello
🔒 Non-Repudiation Guarantee
This signature is cryptographically binding: Once Sarah confirms with her passkey, the instruction is digitally signed using her device's private key. This signature proves that Sarah, and only Sarah, authorized this instruction at this exact moment. It cannot be forged, replayed, or denied.
What the Signature Proves
Legal and Technical Certainty
- Identity: Proves it was Sarah Mitchell's device and biometric
- Intent: Shows Sarah reviewed and approved the exact instruction
- Integrity: Any alteration to the instruction would invalidate the signature
- Timestamp: Records the precise moment of authorization
- Non-repudiation: Sarah cannot later claim she didn't submit this
- Device-bound: Signature came from Sarah's registered device only
Technical Process
Behind the Scenes
When Sarah confirms with Face ID:
- Her device generates a cryptographic signature using her private key
- The signature includes a hash of the instruction content
- The timestamp and device ID are embedded in the signature
- The signed instruction is sent to the firm's backend
- The backend verifies the signature using Sarah's registered public key
- If valid, the instruction is permanently recorded with full audit trail
What Happens Next?
Backend Creates Permanent Record
The firm's backend will now create an immutable customer instruction record with a unique reference code (CREF-XXXX-XXXX). This record includes the signed instruction, timestamp, device ID, and cryptographic proof.