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Shipped2026

SealTender

FHE-encrypted sealed-bid procurement

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Stack

  • Solidity
  • fhEVM
  • FHE
  • TypeScript

Highlights

  • ·End-to-end encrypted bids under fhEVM
  • ·Homomorphic comparison of sealed offers
  • ·Only the winning bid is ever disclosed

Problem

Procurement auctions leak bids. When every bidder can see the others' offers, collusion is trivial and price discovery collapses. Traditional sealed-bid processes require a trusted auctioneer, which is the exact assumption chains are supposed to remove.

Approach

Bids live as ciphertexts under fhEVM. The tender contract uses FHE.min and FHE.select to pick a winner over encrypted values. No party, including the contract operator, sees losing bids. The winner is decrypted and announced; everyone else stays sealed forever.

Outcome

Shipped. A full sealed-bid procurement flow fits into a small contract, with no trusted auctioneer required.