Architecture

ZKPDF enables zero-knowledge verification of PDF documents through cryptographic proofs. The system consists of three main components: PDF processing utilities, zero-knowledge circuits, and a web application.

System Overview

The verification process:

1. PDF document is parsed to extract text and validate digital signatures
2. Verification claims are processed through SP1 zero-knowledge circuits
3. Cryptographic proofs are generated without revealing document content
4. Proofs can be verified on-chain or off-chain

Core Components

PDF Utils (pdf-utils/)

Rust-based PDF processing library designed for zero-knowledge environments. Provides text extraction, signature validation, and unified verification interface with WebAssembly support for browser compatibility.

Circuits (circuits/)

SP1-compatible zero-knowledge circuits containing the main verification library, SP1 program implementation, and proving infrastructure utilities.

App (app/)

Next.js frontend application providing PDF upload, real-time verification, proof generation, and integration with the prover server and WASM modules.

Data Flow

PDF Processing

1. Document upload through web interface
2. Client-side parsing using WebAssembly
3. Text and signature extraction
4. Initial validation

Proof Generation

1. PDF data prepared for SP1 circuits
2. SP1 zkVM executes verification program
3. Zero-knowledge proof generated
4. Public values committed to proof

Verification

1. Proof validated locally or on-chain
2. Results displayed without revealing document content

PDF Support

Performance Characteristics

• Large PDFs require significant memory (8-16GB)
• Proof generation: 20-3 mins depending on mode
• Browser memory limitations for file processing