AgentSkillsCN

rng-crypto-specialist

为赌场游戏设计、实现并审计可证明公平的随机数生成器与加密种子工作流。在定义提交-揭示架构、服务器/客户端种子生命周期、nonce递增、哈希/HMAC结果衍生、无偏范围映射、公平性记录验证，或加密发布签核证据时使用此技能。

SKILL.md
--- frontmatter
name: rng-crypto-specialist
description: Design, implement, and audit provably fair RNG and cryptographic seed workflows for casino games. Use when defining commit-reveal architecture, server/client seed lifecycle, nonce progression, hash/HMAC outcome derivation, bias-free range mapping, fairness transcript verification, or cryptographic release sign-off evidence.

RNG Crypto Specialist

Use this skill to make RNG behavior reproducible, tamper-evident, and independently verifiable.

Workflow

  1. •Define fairness contract before implementation.
  • •Specify game outcomes that are RNG-derived, transcript fields, and reveal timing.
  • •Set immutable rules for server seed rotation, client seed changes, and nonce increments.
  • •Declare what players can verify pre- and post-reveal.
  1. •Choose cryptographic primitives and transcript schema.
  • •Prefer SHA-256 commitments and HMAC-SHA256 outcome derivation unless the system requires otherwise.
  • •Store canonical transcript fields: serverSeedHash, serverSeed (after reveal), clientSeed, nonce, gameId, mode, and outcome.
  • •Define exact string/byte serialization and encoding rules to avoid replay mismatches.
  1. •Enforce bias-free outcome mapping.
  • •Derive randomness from deterministic crypto material only.
  • •Convert random integers to bounded outcome ranges with rejection sampling.
  • •Reject modulo-only mapping when 2^n is not evenly divisible by range size.
  1. •Implement seed and nonce lifecycle controls.
  • •Treat server seed as secret until reveal, then rotate immediately after reveal window.
  • •Keep per-session or per-player nonce monotonic and gap-free.
  • •Block replay or out-of-order nonce acceptance at API boundaries.
  1. •Verify transcripts with deterministic tooling.
  • •Recompute commitment hashes from revealed server seeds.
  • •Recompute expected outcomes from serverSeed, clientSeed, and nonce.
  • •Treat hash mismatches, nonce reuse, or outcome mismatches as hard blockers.
  1. •Produce cryptographic sign-off package.
  • •Deliver algorithm specification, sample transcripts, verification command outputs, and open risks.
  • •Include exact patch plan with file paths for any fixes.

Commands

bash
python3 scripts/verify_provably_fair.py \
  --server-seed "<secret>" \
  --client-seed "<client>" \
  --nonce 0 \
  --range-max 10000

python3 scripts/verify_provably_fair.py \
  --input <transcript.jsonl> \
  --default-range-max 10000

Treat non-zero exits as blocker findings.

Output Contract

When handling RNG crypto tasks, return:

  1. •Protocol Summary: commit-reveal flow, primitives, serialization, and rotation policy.
  2. •Verification Findings: pass/fail for commitments, outcomes, nonce monotonicity, and bias handling.
  3. •Patch Plan: exact files/functions to change and why.
  4. •Evidence: commands run and key outputs.
  5. •Residual Risks: unresolved issues preventing sign-off.

References

  • •references/workflow.md: end-to-end implementation and audit procedure.
  • •references/crypto-primitives.md: approved primitives, mappings, and pitfalls.
  • •references/signoff-template.md: concise report structure for handoff.

Execution Rules

  • •Keep pre-reveal server seeds confidential; never log plaintext secrets in production traces.
  • •Freeze canonical serialization and test vectors before cross-language implementation.
  • •Require rejection sampling for bounded integer mapping unless divisibility is guaranteed.
  • •Mark any unverifiable outcome path as non-compliant.