Why Use Digital Signatures?
Digital signatures verify document authenticity and integrity. They are legally binding in most countries and more secure than handwritten signatures.
Types of PDF Signatures
- Electronic Signature: Image of handwritten signature
- Digital Signature: Cryptographic verification
- Certificate-based: Uses digital certificate
Method 1: Adobe Acrobat
- Open PDF in Acrobat
- Tools > Certificates > Digitally Sign
- Draw signature area
- Select or create digital ID
- Apply signature
Method 2: DocuSign
Upload PDF, add signature fields, sign electronically. Free tier available.
Method 3: HelloSign
Similar to DocuSign. Upload, sign, and download signed PDF.
Method 4: Mac Preview
- Open PDF in Preview
- Tools > Annotate > Signature
- Create signature with trackpad
- Apply to document
Method 5: Create Signature Image
- Sign white paper
- Scan or photograph
- Crop to signature only
- Insert into PDF
Legal Validity
Digital signatures are legally binding under:
- eIDAS (European Union)
- ESIGN Act (United States)
- Electronic Transactions Act (Australia)
Tips
- Use certificate-based signatures for important documents
- Keep signature image secure
- Verify signatures before finalizing