Passed 21 of 22 test cases with the skill, and 15 of 22 without it.
Without skill68%
With skill95%
Checks it passed that the model alone missed
recommends column-by-column GF(2) matrix construction
recommends setting up a univariate polynomial root finding problem
identifies the Piret-Quisquater differential fault attack technique
and 4 more in the full report
6 fixed15 passed either way1 still failing0 broke
Pass-rate lift
+27 pp
Tokens
+19%
Agent turns
0%
Response time
-6%
Model gemini-3.6-flashMeasured 8/19/2026v121 of 22 cases passed with skill
Tokens, turns and time describe resource use, not a dollar price.
See it in action
One of 6 test cases the skill fixed. Same model, same prompt, with and without the skill.
1 of 6
Prompt
Two RSA moduli N1 and N2 share a relationship p2 = p1 + k where k is a small known integer. What algebraic formulation solves for p1?
What was checked, without and with the skill
Checked
Without skill
With skill
recommends setting up a univariate polynomial root finding problem
Missed
Passed
case-15 · gemini-3.6-flash · 8/19/2026 · answers are capped and redacted
What's inside
The instructions your model reads when the skill loads.
SKILL.md18 linessingle file
Cryptography
Scope
Practical cryptanalysis for CTF and pentest engagements: identifying when a cryptographic primitive's structure (custom hash, partial leaks, related primes, bad RNG, weak modes) admits a faster-than-brute-force solver, then implementing that solver in pure Python where possible. Covers RSA-style algebraic factoring, lattice/AGCD recovery, GF(2) linear collapse of "complicated-looking" custom ciphers, smooth-order DLP, differential fault attacks, and Shamir-style secret-sharing recovery over non-prime moduli. Always read source first to detect linearity/algebraic structure before reaching for SageMath or symbolic solvers.
When to use
A challenge or target ships custom crypto (custom hash, custom block cipher, hand-rolled key derivation) and you need to look for affine / GF(2)-linear collapse.
RSA-style primitives with structured primes (p = a·r + b, phi(n) perfect square, multi-prime hint files, common factors).
A service exposes a chosen-ciphertext / chosen-input oracle and you suspect padding-oracle, smooth-order DLP, or Bleichenbacher-style recovery.
AES with fault injection (correct + faulty ciphertext for the same key — Piret-Quisquater DFA).
Shamir secret sharing or threshold schemes with non-prime moduli (2-adic recovery via Lagrange interpolation with valuation tracking).
Core pentesting tools and methodology - Burp Suite usage, Playwright automation, binary analysis, testing methodology, and professional reporting standards.