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Implementing Zero-Knowledge Proof for Authentication · mukul975 | DecimalAI

Implementing Zero Knowledge Proof For Authentication

NewSkillScoreMaintained

implementing-zero-knowledge-proof-for-authentication

Zero-Knowledge Proofs (ZKPs) allow a prover to demonstrate knowledge of a secret (such as a password or private key) without revealing the secret itself. This skill implements the Schnorr identificati

Securityby mukul975

Links this skill to your agents and keeps it current with the author’s updates.

Automatic

Security & AppSec pack

1 · One-time — install the CLI (docs ↗)

pip install decimalai

2 · Get the skill — writes .claude/skills/implementing-zero-knowledge-proof-for-authentication/SKILL.md

decimalai skills pull implementing-zero-knowledge-proof-for-authentication --out .claude/skills/

No CLI? Get the same file — curl · raw file

curl -fsSL --create-dirs -o .claude/skills/implementing-zero-knowledge-proof-for-authentication/SKILL.md https://app.decimal.ai/s/implementing-zero-knowledge-proof-for-authentication/SKILL.md

Raw file: /s/implementing-zero-knowledge-proof-for-authentication/SKILL.md ↗ · machine-readable summary at /s/implementing-zero-knowledge-proof-for-authentication.json ↗

In productionGlobal

how this skill behaves on real traffic · last 30 days

No production data for this skill yet — usage numbers appear here once agents start running it.

Anonymized aggregate across every org using this skill — proof from real production use, not a demo.

Does this skill help? · Benchmark: with vs. withoutsign in to run this on your agents

22 test cases from the publisher’s eval.yaml · each run twice on gemini-3.6-flash — with the skill injected, then without · last run 57d ago

No — -100% lift+5% tokens0% turns0% of whole cases pass with skill (0/22)

Test case	Without → With	Effect	Δ tokens	Δ turns
case-03	✗→✗	＝ Same ✗	—	—
case-17	✗→✗	＝ Same ✗	—	—
case-11	✗→✗	＝ Same ✗	—	—
case-16	✗→✗	＝ Same ✗	—	—
case-15	✗→✗	＝ Same ✗	—	—

Showing 5 of 22 cases

SkillSafety

✓ 3 of 3 passed

Code scan15 of 15 checks clean

0 critical · 0 warning · 0 info — scanner v4 — 7/30/2026

live_secretremote_code_executionreverse_shelldata_exfiltrationssrf_metadataagent_snoopinganti_refusaldestructive_commandsobfuscated_unicodeunicode_homoglyphopaque_blobsuspicious_urltool_overreachtrigger_abuseprompt_injection_phrasing

IntentSafe

LLM judge · does the skill do what it claims

ContentClean

LLM judge · policy & harmful-content review

Source

Imported

mukul975 / Anthropic-Cybersecurity-Skills

skills/implementing-zero-knowledge-proof-for-authentication/SKILL.md

View on GitHub ↗

License Apache-2.0Imported 8/8/2026Version v1Bundled 4 files · scripts

Skill contents

scripts/

references/

SKILL.md

Implementing Zero-Knowledge Proof for Authentication

Overview

Zero-Knowledge Proofs (ZKPs) allow a prover to demonstrate knowledge of a secret (such as a password or private key) without revealing the secret itself. This skill implements the Schnorr identification protocol and a simplified ZKPP (Zero-Knowledge Password Proof) using the discrete logarithm problem, enabling authentication where the server never learns the user's password.

When to Use

When deploying or configuring implementing zero knowledge proof for authentication capabilities in your environment
When establishing security controls aligned to compliance requirements
When building or improving security architecture for this domain
When conducting security assessments that require this implementation

Prerequisites

Familiarity with cryptography concepts and tools
Access to a test or lab environment for safe execution
Python 3.8+ with required dependencies installed
Appropriate authorization for any testing activities

Objectives

Implement Schnorr's identification protocol for ZKP authentication
Build a non-interactive ZKP using Fiat-Shamir heuristic
Implement zero-knowledge password proof (ZKPP)
Demonstrate completeness, soundness, and zero-knowledge properties
Compare ZKP authentication with traditional password verification

Key Concepts

ZKP Properties

| Property | Description | |----------|------------| | Completeness | Honest prover always convinces honest verifier | | Soundness | Dishonest prover cannot convince verifier (except negligible probability) | | Zero-Knowledge | Verifier learns nothing beyond the statement's truth |

Schnorr Protocol

Setup: Public generator g, prime p, q (order of g)
Registration: Prover computes y = g^x mod p (public key from secret x)
Commitment: Prover sends t = g^r mod p (random r)
Challenge: Verifier sends random c
Response: Prover sends s = r + cx mod q
Verify: Check g^s == t y^c mod p

Security Considerations

Use cryptographically secure random number generators
Challenge must be unpredictable (from verifier's perspective)
For non-interactive proofs, use Fiat-Shamir with collision-resistant hash
ZKP alone does not provide forward secrecy; combine with TLS

Validation Criteria

] Honest prover always verifies successfully (completeness)
] Random response without secret does not verify (soundness)
] Server never receives the secret value
] Non-interactive proof is verifiable offline
] Multiple authentications produce different transcripts
] Protocol resists replay attacks

Illustrative Want to see what implementing-zero-knowledge-proof-for-authentication would put in front of your model? Preview the rendered body and check its trigger phrases — no LLM call, no signup.

Latest benchmark · publisher runVerified

7/28/2026, 10:15 UTC · 22 cases

Lift

-100%

0% vs 100%

Agent turns

0%

1.0 vs 1.0

Tokens

+5%

2,552 vs 2,432.68

fail → fail · 22

Per-case results (22)

Case	Status	Duration (ms)			Turns			Tokens			Tool calls
Case	Status	Without	With	Δ	Without	With	Δ	Without	With	Δ	Without	With	Δ
case-03 Design an Elliptic Curve Diffie-Hellman (ECDH) key exchange protocol with AES-GCM encryption for securing API telemetry packets between edge sensors and a backend server. Detail the ephemeral key generation and symmetric payload encryption steps.	fail→fail	—	—	—	—	—	—	—	—	—	—	—	—
case-17 In interactive Schnorr identification protocol, who generates challenge $c$, and what bounds must $c$ satisfy?	fail→fail	—	—	—	—	—	—	—	—	—	—	—	—
case-11 Write an automated unit test procedure to test the soundness property of a Schnorr ZKP authentication module.	fail→fail	—	—	—	—	—	—	—	—	—	—	—	—
case-16 Specify the exact mathematical criteria linking prime modulus $p$, subgroup prime order $q$, and generator $g$ in Schnorr identification protocol parameter setup.	fail→fail	—	—	—	—	—	—	—	—	—	—	—	—
case-15 In Python, a developer uses `random.randint(1, q-1)` to select ephemeral nonce $r$ for Schnorr identification. Identify the security flaw and specify the standard Python module for generating $r$.	fail→fail	—	—	—	—	—	—	—	—	—	—	—	—
case-19 In ZKPP authentication, a developer converts password string 'P@ssword123' directly into integer $x$ by ASCII byte conversion. What standard cryptographic transformation should be applied to textual password to construct secret exponent $x$?	fail→fail	—	—	—	—	—	—	—	—	—	—	—	—
case-13 When transmitting a non-interactive Fiat-Shamir Schnorr ZKP over HTTP, how can replay attacks be prevented if an attacker intercepts proof payload $(t, s)$?	fail→fail	—	—	—	—	—	—	—	—	—	—	—	—
case-08 In Schnorr identification protocol, a developer proposes optimizing server throughput by reusing ephemeral nonce $r$ across multiple challenges $c_1$ and $c_2$. Explain why this is insecure and show the recovery equation for secret key $x$.	fail→fail	—	—	—	—	—	—	—	—	—	—	—	—
case-21 Which underlying cryptographic hard problem ensures a prover cannot compute secret key $x$ from public key $y = g^x \bmod p$ in Schnorr authentication?	fail→fail	—	—	—	—	—	—	—	—	—	—	—	—
case-12 To demonstrate zero knowledge in Schnorr protocol, explain how an offline simulator constructs an authentic-looking transcript $(t, c, s)$ without knowing secret key $x$.	fail→fail	—	—	—	—	—	—	—	—	—	—	—	—
case-10 Write an automated Python unit test procedure to verify the completeness property of a Schnorr identification implementation.	fail→fail	—	—	—	—	—	—	—	—	—	—	—	—
case-09 Provide the mathematical proof showing why $g^s \equiv t \cdot y^c \pmod p$ holds in Schnorr identification, starting from response definition $s = r + c \cdot x \pmod q$.	fail→fail	—	—	—	—	—	—	—	—	—	—	—	—
case-07 We want to transform an interactive Schnorr identification into a non-interactive proof using Fiat-Shamir heuristic. A developer suggests calculating challenge $c = \text{Hash}(x \parallel t)$. Evaluate this proposed input and state the correct hash input components.	fail→fail	—	—	—	—	—	—	—	—	—	—	—	—
case-14 In a Zero-Knowledge Password Proof (ZKPP) user registration endpoint, what key value does the client derive from user password $x$ and transmit to server database?	fail→fail	—	—	—	—	—	—	—	—	—	—	—	—
case-20 Does implementing interactive Schnorr ZKP authentication eliminate the requirement for TLS transport security on web sockets? Explain transport layer requirements.	fail→fail	—	—	—	—	—	—	—	—	—	—	—	—
case-22 When a verifier receives response $s$ in Schnorr identification protocol, what boundary checks must be performed on $s$ prior to exponentiation?	fail→fail	—	—	—	—	—	—	—	—	—	—	—	—
case-02 Configure an automated Python service to sign document hashes using RSA-PSS digital signatures with PyCryptodome. Specify the recommended key size, hash algorithm, and PSS salt length parameters.	fail→fail	—	—	—	—	—	—	—	—	—	—	—	—
case-01 Design an OAuth2 Authorization Code flow with Proof Key for Code Exchange (PKCE) for a SPA client connecting to an identity provider. Provide the sequence of requests, parameters, and verification steps for code_verifier and code_challenge.	fail→fail	—	—	—	—	—	—	—	—	—	—	—	—
case-04 I am writing a Python script for Schnorr identification protocol. During commitment generation, I am tempted to compute $t = g^x \bmod p$ using the secret key $x$ directly to avoid managing extra variables. Specify how commitment $t$ must be generated.	fail→fail	—	—	—	—	—	—	—	—	—	—	—	—
case-05 In Schnorr identification implementation, a developer writes the response line as `s = (r + c * x) % p`, reducing modulo the large prime $p$. Is this correct, or should it use prime order $q$? State the correct modulus and mathematical reason.	fail→fail	—	—	—	—	—	—	—	—	—	—	—	—
case-06 Write the verification equation evaluated by the verifier in Schnorr's identification protocol given public key $y$, generator $g$, prime $p$, response $s$, commitment $t$, and challenge $c$.	fail→fail	—	—	—	—	—	—	—	—	—	—	—	—
case-18 Analyze database breach impact differences between storing Argon2 password hashes versus storing Schnorr ZKPP public keys $y = g^x \bmod p$.	fail→fail	—	—	—	—	—	—	—	—	—	—	—	—

These cases were also screened by the skill’s intent / safety pass.See the Trust review ↗Reproduce this benchmark in Colab ↗

How this skill was measured

DecimalAI ran this skill against gemini-3.6-flash twice over the same eval suite — once with the skill loaded and once without — and compared the two runs case by case. 22 cases were attempted. The headline lift of -100 percentage points is the difference between those two pass rates over the 22 comparable cases. 1 case got worse with the skill loaded, and it is included in that figure.

Model measured: gemini-3.6-flash
Graded by: gemini-3.6-flash
Grading method: judged
Verification: verified
Pass rate without the skill: 100%
Pass rate with the skill: 0%
Cases attempted: 22
Cases counted toward lift: 22
Cases that regressed: 1
Skill version measured: v1
Run completed: 7/28/2026, 10:15 UTC

The per-case answers from this run were removed by the retention sweep, so the case table below shows the verdicts without the text either arm produced. The counts above were recorded at the time and are unaffected. Answers are now kept for 180 days.

SkillScore blends 4 signalsno signals yet

BenchmarkRun a verified benchmark with positive lift

Live evalNeeds ≥10 evaluated traces in 30 days

AI ratingNeeds ≥10 rated traces

AdoptionNeeds ≥10 serves across ≥2 orgs in 30 days

No signals yet — run a benchmark or collect evaluated traces to earn a score.

Verified on gemini-3.6-flash · re-tested 56 days ago

Other measured skills in the registry, with their headline benchmark lift.