Skills Development Advanced Crypto and Mobile Forensics

Advanced Crypto and Mobile Forensics

v20260903
competition-crypto-mobile
A specialized downstream skill for complex CTF challenges, focusing on cryptographic analysis, steganography, and mobile system forensics. It guides the user through recovering complex data chains, such as decoding blobs, tracing cryptographic transforms (keys, IVs, nonces), inspecting hidden media payloads, and analyzing mobile trust boundaries (e.g., APK/IPA signing logic, local storage, SSL pinning). This skill is designed to be used only after a main sandbox orchestrator has established the operational context.
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Overview

Competition Crypto Mobile

Use this skill only as a downstream specialization after $ctf-sandbox-orchestrator is already active and has established sandbox assumptions, node ownership, and evidence priorities. If that has not happened yet, return to $ctf-sandbox-orchestrator first.

Use this skill when the active challenge depends on recovering a transform chain, hidden media payload, mobile signing path, or local trust boundary.

Reply in Simplified Chinese unless the user explicitly requests English.

Quick Start

  1. Decide whether the dominant path is crypto, stego, or mobile.
  2. Recover transforms in order; do not jump straight to the fanciest algorithm.
  3. Record exact parameters and boundaries that affect the result.
  4. Hook the narrowest mobile boundary that proves the behavior.
  5. Reproduce the plaintext, payload, signed request, or accepted branch.

Workflow

1. Crypto And Encoding

  • Reconstruct the chain step by step: container, compression, encoding, xor or substitution, crypto, integrity, final parse.
  • Keep exact keys, IVs, nonces, salts, tags, offsets, and byte order.

2. Stego

  • Inspect metadata, chunk layout, palettes, alpha planes, LSBs, thumbnails, trailers, and transcoding artifacts.
  • Rank decode attempts by evidence, not by brute-force curiosity.

3. Mobile

  • Start with manifest or plist, exported components, deeplinks, native libs, shared prefs, local DBs, and configs.
  • Trace signer logic, token storage, SSL pinning, protobuf or RPC boundaries, and native bridge calls.

Read This Reference

  • Load references/crypto-mobile.md for the transform checklist, hook targets, and evidence packaging.
  • If the task is specifically about Android dynamic tracing, signer hooks, JNI boundaries, or pinning checks, prefer $competition-android-hooking.
  • If the task is specifically about iOS runtime tracing, Keychain access, Objective-C or Swift hooks, or pinning checks inside an IPA, prefer $competition-ios-runtime.
  • If the task is specifically about media carriers, hidden channels, thumbnails, or appended trailers, prefer $competition-stego-media.

What To Preserve

  • Decisive bytes proving each decode stage
  • Hook points, signed strings, headers, and local storage paths
  • Component names, protobuf fields, channel-specific outputs, or trailer offsets
Info
Category Development
Name competition-crypto-mobile
Version v20260903
Size 2.57KB
Updated At 2026-09-05
Language