fix: replace GMP primality check with Baillie-PSW via num-bigint-dig#1
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lucasfernandes wants to merge 8 commits into
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fix: replace GMP primality check with Baillie-PSW via num-bigint-dig#1lucasfernandes wants to merge 8 commits into
lucasfernandes wants to merge 8 commits into
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The primality check in hash_prime was delegating to GMP's mpz_probab_prime_p, which used Miller-Rabin only in versions <= 6.1.2. Miller-Rabin alone is vulnerable to adversarially crafted inputs, allowing a malicious prover to forge VDF proofs. Changes: - classgroup/Cargo.toml: add num-bigint-dig (Baillie-PSW, pure Rust, static) - classgroup/build.rs: assert GMP >= 6.2.0 at compile time as a fallback guard - classgroup/src/gmp_classgroup/mod.rs: replace __gmpz_probab_prime_p with probably_prime from num-bigint-dig (Miller-Rabin + Lucas test) - vdf/src/proof_wesolowski.rs: remove dead code block that blocked compilation - .cargo/config.toml: linker path for GMP on macOS Apple Silicon (Homebrew) Ref: poanetwork#25 See: https://eprint.iacr.org/2018/749.pdf
lucasfernandes
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May 22, 2026
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
…rror) Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
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Summary
repsinprobab_prime(2)does not solve the issue. More Miller-Rabin rounds only add computation time — they do not fix the adversarial input problem. Here we used 20 to follow the lib patternprobably_prime(&n, iterations.max(20) as usize). Since more iterations doesn't help anyways.IMPORTANT: on file vdf/src/proof_wesolowski.rs an if must've removed because of compiler version updated.
References