Security Architecture

Security Philosophy

TimeProof’s security is built on a principle: minimize what you need to trust. Instead of asking you to trust TimeProof’s servers, the system is designed so that the most critical data — your timestamp proofs — lives on a decentralized blockchain that no one controls.

This is defense in depth. Even if one layer is compromised, the layers beneath it protect your data.

Layer 1: Blockchain Immutability

The foundation of TimeProof’s security is the Polygon blockchain:

Property	What It Means
Immutable	Once written, data cannot be changed or deleted
Decentralized	No single entity controls the network
Transparent	Anyone can read and verify the data
Consensus-protected	Changes require agreement from thousands of validators

When a hash is anchored on the blockchain, it’s permanent. TimeProof cannot modify it. A hacker cannot modify it. A court order cannot modify it. The data is protected by the same consensus mechanism that secures billions of dollars in cryptocurrency.

Smart Contract Design

The TimeProof smart contract is intentionally minimal:

Single purpose: Accept a hash, record it with a timestamp
No admin functions that could override or delete data
No upgrade proxy — the contract is deployed once and cannot be changed
Verifiable source — the contract code may be published on Polygonscan

A simpler contract is a more secure contract. Every line of code is a potential vulnerability. By keeping the contract minimal, the attack surface is as small as possible.

Layer 2: Client-Side Hashing

Your files never leave your machine. This eliminates entire categories of security risks:

Risk	Eliminated?	How
File interception in transit	✅	Files aren’t transmitted
Server-side data breach exposing files	✅	Server never has files
Insider threat (employee access)	✅	No files to access
Legal subpoena for file contents	✅	TimeProof doesn’t have them
Storage encryption failures	✅	No file storage exists

The SHA-256 hash is computed in your browser using the Web Crypto API — a hardware-accelerated cryptographic implementation built into modern browsers. The hash is the only data sent to TimeProof.

Layer 3: Wallet-Based Authentication

TimeProof uses Sign-In with Ethereum (SIWE) instead of passwords:

Feature	Traditional Auth	TimeProof (SIWE)
Credential type	Password	Cryptographic signature
Server stores	Password hash	Nothing (stateless verification)
Phishing risk	High	Low (signature is domain-bound)
Credential reuse	Common problem	Not possible (keys are unique)
Brute force risk	Depends on password strength	Infeasible (256-bit keys)
Recovery	Email reset (attack vector)	Wallet seed phrase (user-controlled)

With SIWE, there’s no password database to breach. Your private key never leaves your wallet — the server only sees a signature that proves wallet ownership.

Layer 4: Session Security

After authentication, sessions are protected by:

Protection	Implementation
HTTP-only cookies	JavaScript cannot access the session token (XSS protection)
Secure flag	Cookie transmitted only over HTTPS (production)
SameSite: Strict	Cookie not sent with cross-origin requests (CSRF protection)
Server-side sessions	Session state stored server-side, only an opaque ID in the cookie
Session expiration	Automatic timeout after inactivity

Why Not JWTs?

Some APIs use JSON Web Tokens (JWTs) stored in localStorage. TimeProof uses server-side sessions instead because:

JWTs in localStorage are vulnerable to XSS attacks
JWTs cannot be revoked once issued
Server-side sessions can be immediately invalidated on sign-out
HTTP-only cookies are inaccessible to JavaScript

Layer 5: Data Protection

Database Security

Encryption at rest — database storage is encrypted
Regular backups — automated backup schedule with point-in-time recovery
Principle of least privilege — database access restricted to necessary services
Input validation — all API inputs validated and sanitized

Payment Security

Stripe handles payments — credit card data never touches TimeProof’s servers
Webhook verification — Stripe webhooks verified via cryptographic signatures
No financial data stored — only Stripe session references, not card numbers

Identity Verification

Stripe Identity handles verification — ID documents processed by Stripe, not TimeProof
Minimal data — TimeProof receives verification status, not identity documents
JWS attestation — identity proof is cryptographically signed, self-verifiable

Layer 6: Network Layer Security

Measure	Purpose
HTTPS everywhere	Encrypts all client-server communication
Rate limiting	Prevents abuse and denial-of-service attacks
CORS policy	Restricts which domains can call the API
Input sanitization	Prevents injection attacks (SQL, XSS, etc.)
Content Security Policy	Restricts what resources the browser can load

Threat Model

Threat	Mitigation	Impact If Breached
Server compromise	Database encryption, backups, blockchain immutability	Account data exposure; timestamps remain safe on blockchain
Man-in-the-middle	HTTPS, certificate pinning	Cannot intercept because all traffic encrypted
XSS attack	HTTP-only cookies, CSP, input sanitization	Cannot steal sessions or inject scripts
CSRF attack	SameSite cookies, origin checking	Cannot forge requests from other sites
Blockchain attack	Polygon’s consensus mechanism (thousands of validators)	Practically impossible for historical data
File exposure	Client-side hashing (files never transmitted)	Cannot expose what was never received

What You Should Do

TimeProof’s architecture handles most security concerns, but you can strengthen your security:

Protect your wallet seed phrase — never share it, store it offline
Use a hardware wallet for high-value timestamps (Ledger, Trezor)
Download and back up certificates — don’t rely solely on the dashboard
Sign out on shared devices — terminate your session when done
Keep your browser updated — security patches protect the client-side hashing

Privacy and Your Files — privacy protection details
Open Source Verification — verify without trusting TimeProof
What Happens If TimeProof Goes Down? — business continuity
API Authentication — SIWE authentication details