Introduction
International guide to e-signature laws: ESIGN, eIDAS, UETA, and global acceptance. This is an advanced guide for experienced users and developers. We'll dive deep into the technical details, edge cases, and professional workflows. Whether you're using PDFly's free online tools or building your own workflow, this guide covers everything you need to know about the legal validity of electronic signatures by country.
Understanding Security
PDF security protects sensitive documents through encryption, passwords, permissions, and digital signatures. From simple password protection to enterprise-grade AES-256 encryption, understanding security options ensures your documents remain confidential and tamper-proof.
Key Concepts You Need to Know
- AES-256 encryption is the current gold standard for PDF security
- User passwords restrict opening; owner passwords restrict editing and printing
- Permission settings control printing, copying, editing, and form filling
- Digital signatures use PKI cryptography to verify document authenticity
- Redaction must remove both visible text and underlying data to be effective
Tips & Best Practices
Use strong passwords — at least 12 characters with mixed case, numbers, and symbols
AES-256 encryption is recommended for sensitive documents
Set appropriate permissions — restrict editing and copying for sensitive documents
Remove metadata before sharing to protect privacy
Test password-protected files by opening them on a different device
Common Mistakes to Avoid
- Using weak passwords makes encryption easily breakable
- Forgetting the password means permanent loss of access — store it safely
- Redaction by covering with rectangles is not secure — use proper redaction tools
- Not removing metadata can leak author names, edit history, and GPS data
- Relying only on permissions (without encryption) is easily bypassed
Comparing Your Options
| Feature | Option A | Option B |
|---|---|---|
| Encryption | AES-256 | AES-128 |
| Security Level | Maximum | Good |
| Compatibility | Modern viewers | All viewers |
| Best For | Highly sensitive documents | General protection |
Code Example
// Example: Using PDFly's client-side API
const file = document.getElementById('file-input').files[0];
const arrayBuffer = await file.arrayBuffer();
// Process PDF entirely in the browser
const result = await pdfly.process(arrayBuffer, {
operation: 'compress',
level: 'medium'
});
// Download the result
const blob = new Blob([result], { type: 'application/pdf' });
const url = URL.createObjectURL(blob);
window.open(url);