LoongKEM
Lattices · LWE · niccs.org.cn(opens in a new tab)
- Programmes
- NGCC R1
- Status
- NGCC round 1
- Security flags
- Broken (2 of 4 sets) · Implementation findings (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 |
|---|---|---|---|---|---|---|---|
| Loong128 BrokenImplementation findings | 128-bit | 1,472 | 1,512 | 2,984 | 1.62 ms | 1.63 ms | 1.64 ms |
| Loong256 BrokenImplementation findings | 256-bit | 3,248 | 3,520 | 6,768 | 3.95 ms | 3.97 ms | 4.00 ms |
| Loong384 Implementation findings | 384-bit | 6,444 | 6,680 | 13,124 | 12.90 ms | 12.95 ms | 13.03 ms |
| Loong512 Implementation findings | 512-bit | 10,640 | 10,848 | 21,488 | 20.97 ms | 20.72 ms | 20.86 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
- Broken (Loong128, Loong256): Public consistency equations recover shared secrets with practical lattice reduction (Xie).
- Implementation findings (all parameter sets): A faulty rejection mask in the submitted decapsulation returns the true shared secret for modified ciphertexts (Saarinen). Its rejection key also hashes the re-encryption instead of the received ciphertext, so decapsulation queries recover the secret key (Saarinen). Full findings report(opens in a new tab)
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.