FHE auctions

Implements bit slice approach for private auctions as described in 2002/189.

Uses tfhe-rs to implement boolean gates using p-encoding technique as described in 2023/1589.

TFHE parameters are obtained via concrete-optimiser and has 128-bit of security.

Costs

Auction circuit runtime increase linearly with $k$ and $n$, where $n$ is no. of bidders and $k$ is bits in bid (for ex, 64 bits, 128 bits)

Since a bid of $k$ bits is represented as $k$ LWE ciphertexts, each bidder needs to upload $k$ LWE ciphertexts.

Test

On x86_64 based machines set tfhe-rs dependecy in cargo.toml as

tfhe = {git = "https://github.com/Janmajayamall/tfhe-rs.git", features = ["boolean", "shortint", "integer", "p-encoding","x86_64-unix"]}

On apple-silicon or aarch-64 based machines set tfhe-rs dependecy in cargo.toml as

tfhe = {git = "https://github.com/Janmajayamall/tfhe-rs.git", features = ["boolean", "shortint", "integer", "p-encoding","aarch64-unix"]}

then run cargo test --release tests::auction_circuit_works -- --nocapture