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saymrwulf
127ae61d11
The return code the voter checks is now genuinely computed by the CCs from the submitted ciphertext, not looked up from the card: - returncode_extract.go: after a ballot is accepted, the server asks each CC to exponentiate E2 by its return-code key (product over CCs = Enc(vote^Σk)), then each CC contributes a partial-decryption factor; the server recovers vote^Σk, which equals the card base prime_sel^Σk, and looks up the short code. - The server returns that code to the voter, who checks it against the card for the chosen option; a mismatch aborts with a clear error. Soundness test: a malicious client that encrypts option A for the tally (E1) but option B in the return-code channel (E2) is REJECTED by the plaintext-equality proof — so the code shown always reflects the tallied vote. This closes the cast-as-intended gap (the old return codes were decorative, finding F16). Card lCC now uses a fixed tau so extraction can recompute it without learning the option up front. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> |
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| elgamal | ||
| hash | ||
| kdf | ||
| math | ||
| mixnet | ||
| party | ||
| protocol | ||
| returncodes | ||
| serialize | ||
| symmetric | ||
| transport | ||
| transportsec | ||
| verify | ||
| zkp | ||