HEP-QC
Hybrid Equivalent Punctured and Quasi-Cyclic
Code-based · QCSD · niccs.org.cn(opens in a new tab)
- Programmes
- NGCC R1
- Status
- NGCC round 1
- Security flags
- Broken (1 of 3 sets) · Implementation findings (all sets) · Warning (all sets)
Third-party findings: full report on ngcc.dev(opens in a new tab).
Parameter sets
| Parameter set | Level | pk (B) | ct (B) | pk+ct (B) | Keygen | Encaps | Decaps |
|---|---|---|---|---|---|---|---|
| HEP-QC-1 Implementation findingsWarning | 128-bit | 285,889 | 4,433 | 290,322 | 63.06 ms | 3.55 ms | 61.33 ms |
| HEP-QC-5 Implementation findingsWarning | 256-bit | 1,852,485 | 14,421 | 1,866,906 | 235.79 ms | 23.07 ms | 214.49 ms |
| HEP-QC-7 BrokenImplementation findingsWarning | 512-bit | 12,644,449 | 49,297 | 12,693,746 | 1.26 s | 155.20 ms | 831.15 ms |
Wall-clock times vary between runs and machines (CPU frequency scaling, other tenants on cloud VMs); cycle counts are the steadier basis for comparison.
Security flags
- Implementation findings (all parameter sets): The submitted code produces reproducible secret keys and a reproducible first encapsulation in each process (Saarinen). Full findings report(opens in a new tab)
- Warning (all parameter sets): Repeated public columns distinguish the public key from random in linear time, refuting the EPC-P assumption. Structure recovery in minutes is reported but not confirmed (Xie).
- Broken (HEP-QC-7): Key generation has at most 2^256 possible seeds, below the 512-bit target (Saarinen).
History
- Update
NGCC round 1: we checked every confirmed critical and high-severity finding on ngcc.dev against our data, and the PKC Forum, the ngcc-harness issues, the public analysis repositories and ePrint for findings ngcc.dev does not list. New broken flags: OPS-DSA, whose specified challenge sampler allows forgery from the public key in 2^39 to 2^90 trials (Xiong and Wang); the compact SQIsign2D2 sets, where one signature yields forgeries on fresh messages (Feussner); BAG-Piglet, whose specified rejection key gives key recovery from decapsulation queries (Saarinen); MAMBA-Viper-384 and -512, whose specification derives every session secret from a 256-bit seed (Saarinen); FlexTree-160, where verifiers that follow the specification accept forgeries after about 2^40 work (Kudinov); TRINE-128, whose specified unsalted round seeds allow forgery in about 2^95 work (Feussner); and UVW-256 signatures, which leak an equivalent signing key as at UVW-128 (Feussner, extended by Saarinen). New warnings: HEP-QC, whose public key is distinguishable from random (Xie), and Rhyme-SHAKE-128, where a signer that follows the specified rejection bound leaks its secret (Feussner). New implementation notes cover rejection keys over the re-encryption (CheetahKEM, LoongKEM), partial FO checks (QUBE), buffer overflows (Amoeba, MORNING-ATLAS), 32-bit message lengths (Aigis-Sig+, CS), message compression and short prehashes (COMPASS-SIG, VDOO, Amoeba), wrapper boundaries and signed-message opening (VDOO, MORNING-ATLAS), malleable encodings (SQIsignTriangle) and fail-open key generation (ZEN). Each flag credits and links its finding.