Is there any way we can attach Digital signature to Invoice pdf? We are on E1 9.1 Tools 9.1.5.5

Is there any way we can attach Digital signature to Invoice pdf? We are on E1 9.1 Tools 9.1.5.5

Client Requirement:

1. 20+ Distribution Centers (Billing centers) with 1000+ invoice printing per day per center.

2. To embed  the digital signature in the Tax Invoice generated from JDE based on the billing center .

3. The digital signature file will be different for each billing center.

4. Single invoice with multiple pages. Digital Signature required on each page.

4. Need to upload Digital Signature through Portable storage/USB storage and will not be stored on Server location due to security reason.