Build Your First zkPDF Proof I Vikas Rushi

Sun, Nov 2, 2025, 12:00 AM

Vikas Rushi presents the concept of zkPDF, a framework for generating zero-knowledge proofs from digitally signed PDFs. The system enables users to prove statements derived from trusted documents—like age verification, ownership of degrees, or bank transactions—without revealing the full file. By extracting signatures and document data, zkPDF bridges Web2-signed documents (e.g., DigiLocker, DocuSign) into Web3 verifiable proofs. These proofs use the SP1 prover network to create Groth16 or PlonK proofs, which can be verified on EVM-compatible blockchains such as Ethereum and Arbitrum. Rushi explains that zkPDF leverages the public keys of government or institutional authorities to validate authenticity and allows users to make verifiable claims (e.g., “over 18”) using minimal disclosure. He then walks through the technical workflow, from uploading a PDF and extracting its signature to generating and verifying proofs onchain. The demo shows how users can verify whether a PDF is compatible with the zkPDF stack and produce proofs using two core methods: extract + verify and substring with offset. Vikas highlights current limitations—proof generation happens server-side due to computational constraints—and previews plans to make zkPDF client-side. The talk covers integration steps with SP1 circuits, sample Rust libraries, and pre-built smart contracts for verifying proofs. He concludes by showing how commitments prevent replay attacks, benchmarks proof sizes and times (31–52 seconds), and encourages developers to experiment with API endpoints, templates, and zkPDF’s GitHub repository for building verifiable Web3 document systems. 00:00 – Introduction: why zkPDF matters 00:34 – Web2 signed data and government PDFs 01:05 – Use cases: KYC, finance, and age proofs 01:29 – Proving statements from trusted documents 01:50 – Importance of document signers and authorities 02:16 – Indian government PDF signature example 02:41 – How the zkPDF stack works (SP1 prover, verifier contract) 03:37 – Proof generation on server-side 03:59 – Computational limits and client-side roadmap 04:19 – Compatibility check: verifying signatures in PDFs 05:19 – Demonstration: extract and verify method 06:00 – Substring with offset verification 06:30 – Repo structure and setup overview 06:55 – Environment variables and SP1 access 07:16 – Inputs, outputs, and commitments 08:03 – Proof generation options (local vs. ProNet API) 08:25 – Live demo: proof request and generation 09:22 – Proof verification onchain/offchain 10:14 – API reference: verify and extract methods 11:07 – Extracting text and committing proofs onchain 11:37 – Smart contract verification flow 11:58 – Document commitments and replay protection 13:17 – Signature algorithms and support (RSA-SHA) 14:25 – PDF compatibility and limitations 14:44 – Client-side feasibility 15:22 – Integration guide for zkPDF APIs 15:48 – Accessing SP1 ProNet and dashboards 17:45 – Benchmarks: proof time and gas cost 18:10 – Closing remarks and resources _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 🇮🇳 *ETHGlobal New Delhi* This workshop is specifically for ETHGlobal New Delhi, a 3-day hackathon held September 19-21 at the India International Convention & Expo Centre, bringing together the most skilled web3 developers, designers and product builders from all around the globe for a weekend-long adventure to advance the Ethereum ecosystem! Watch the full ETHGlobal New Delhi 2025 playlist here: https://www.youtube.com/playlist?list=PLXzKMXK2aHh7zCFW3hBqatZ18rQaYeEJL _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ✅ *Follow Ethreum Foundation* X: https://x.com/ethereumfndn ✅ *Follow ETHGlobal* X: https://x.com/ETHGlobal​ Warpcast: https://warpcast.com/ethglobal Website: https://ethglobal.com YouTube: https://www.youtube.com/c/ETHGlobal _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _Are you interested in Ethereum development and entrepreneurship?_ 👉 Sign up for the next ETHGlobal event: https://ethglobal.com/events 🎁 Get exclusive access and perks with ETHGlobal Plus! https://ethglobal.com/plus 📣 Want us to throw an event in your city? Tell us where! https://ethglobal.com/city