Digital Signature Capture

Capture, store, and apply electronic signatures to forms with legal validity

Overview

Digital Signature Capture lets you sign PDF forms electronically — by drawing, typing, or uploading a signature image — and applies that signature directly into PDF signature fields without printing or scanning. Every applied signature is embedded into the final PDF using the ReportLab canvas overlaid on the AcroForm structure via pdfrw, with the signature image placed at the exact {page, x0, y0, x1, y1} coordinates of the signature field. The resulting PDF includes a cryptographic seal: any modification to the signed document after the fact invalidates the signature, detectable on audit.

Beyond the visual signature, each signing action captures a metadata record — timestamp, authenticated user identity, IP address, browser and OS — that establishes the evidentiary basis for legal validity under the ESIGN Act (2000) and UETA. This metadata is attached to the filled PDF and logged in the session audit trail, giving legal, healthcare, and financial organizations the attribution and record-retention evidence regulators require.

Signatures can be saved to a personal library and applied to future forms in one click. For workflows requiring signatures from multiple parties — engagement letters, settlement agreements, benefit elections — co-signing sends sequential signing links and accumulates each signature with its own independent metadata before generating the final signed document.

Key Capabilities

• Multiple Capture Methods: Draw with mouse/touchpad, touchscreen, stylus, or upload image
• Signature Library: Save signatures for reuse across forms
• Initial Capture: Separate initials for documents requiring both signature and initials
• Typed Signatures: Generate signature from typed name in various fonts
• Multiple Signatures: Store different signatures (personal, professional, authorized representative)
• Auto-Apply: Automatically insert saved signature into all signature fields
• Co-Signing: Multi-party signing with sequential or parallel workflows
• Signature Metadata: Timestamp, user identity, IP address, and device info for audit trail
• Legal Compliance: ESIGN Act and UETA compliant signature capture
• Signature Verification: Optional 2FA requirement before applying signature
• Clear/Redo: Retry signature capture until satisfied with appearance
• Signature Preview: See how signature will appear on form before applying

How It Works

1. Capture Signature:

   • Draw: Use mouse, touchpad, or touchscreen to draw signature
   • Type: Enter name, system generates stylized signature in chosen font
   • Upload: Upload image of handwritten signature (scanned or photographed)

2. Refine Appearance:

   • Adjust thickness, opacity, color (black for formal documents)
   • Preview on white background to ensure readability
   • Redo until satisfied

3. Save to Library:

   • Name signature: "John Smith - Professional", "Mary Doe - Personal"
   • Mark as default for automatic application
   • Optionally set 2FA requirement for this signature (high-security scenarios)

4. Apply to Forms:

   • During form filling session, click signature field
   • Select saved signature from library
   • Signature image embedded into PDF at the field's coordinate position; metadata record (date, time, user, IP, device) attached to session
   • Optional: Add text annotations (title, date signed, etc.)

5. Multi-Party Signing:

   • First signer fills and signs form
   • System generates unique signing link for next signer
   • Second signer reviews form, adds their signature with independent metadata
   • Process repeats for additional signers
   • Final signed document generated with complete, ordered audit trail

Use Cases

Digital signature capture is most common in legal, healthcare, and financial workflows where wet signatures have historically caused delays. Attorneys collect client signatures on engagement letters and settlement agreements without printing or scanning, medical offices capture patient consent remotely before the appointment, and financial institutions gather account-opening signatures with the timestamp and attribution metadata required for legal validity under ESIGN and UETA.

Benefits

• No Printing Required: Sign forms entirely digitally without paper
• Consistency: Saved signatures look identical across all documents
• Time Savings: Sign multiple forms in seconds with saved signature
• Legal Validity: Metadata establishes evidentiary basis under ESIGN Act
• Audit Trail: Complete record of who signed what, when, from where
• Accessibility: Sign on any device (desktop, tablet, smartphone)
• Professional Appearance: Clean, consistent signature presentation
• Remote Signing: Co-signing enables signing from anywhere
• Tamper Evidence: Cryptographic seal detects post-signing modifications

Security & Privacy

Signature Protection:

• Signatures encrypted at rest in signature library
• 2FA requirement option (SMS via Twilio 7.11.1, or authenticator app) before applying high-value signatures
• Password protection for signature library access
• Biometric authentication support (fingerprint, face ID) on supported devices

Metadata Capture:

• Timestamp (exact date and time signed)
• User identity (email, name, authenticated via JWT)
• IP address (geographic location)
• Device information (browser, OS)
• Authentication method used for the session

Tamper Detection:

• Signed PDFs include cryptographic seal via PDF signing pipeline
• Modifications after signing invalidate the signature — detectable in any standards-compliant PDF reader
• Audit log records if document was accessed or altered post-signature

Access Control:

• All signature library data scoped to workspaceId and protected via the shared JWT authentication middleware running in both the .NET and Python service layers
• Private signatures visible only to owner
• Shared signatures for authorized representatives (e.g., CEO signature for company documents)

Common Questions