docs(10_Wiki): Topic_Business/General/Graphic/Programming을 Topics/ 하위로 이동

최상위 10_Wiki/Topic_*였던 4개 카테고리 폴더를 10_Wiki/Topics/Topic_* 로 재배치. 콘텐츠 변경 없음(순수 폴더 이동) — Topics/ 하위 나머지 폴더는 이미 지난 커밋에서 전부 정리된 상태(잔존 항목은 에이전트 운영 상태 및 사용자가 보존을 요청한 업데이트0615/무제 3.canvas 뿐).
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+---
+id: wiki-2026-0508-code-obfuscation
+title: Code Obfuscation
+category: 10_Wiki/Topics
+status: verified
+canonical_id: self
+aliases: [Obfuscation, Anti-Reverse Engineering]
+duplicate_of: none
+source_trust_level: A
+confidence_score: 0.9
+verification_status: applied
+tags: [security, reverse-engineering, drm, javascript]
+raw_sources: []
+last_reinforced: 2026-05-10
+github_commit: pending
+tech_stack:
+  language: JavaScript/C++
+  framework: obfuscator.io/LLVM-Obfuscator
+---
+
+# Code Obfuscation
+
+## 매 한 줄
+> **"매 reverse-engineering cost 의 raise — semantic 보존하면서 readability 파괴"**. Crypto 처럼 secrecy 가 아닌 cost-shifting — determined attacker 는 매 결국 풀 수 있음. 매 modern usage: anti-piracy, anti-cheating, license validation, 매 LLM-based deobfuscation 의 등장으로 의미 retreat.
+
+## 매 핵심
+
+### 매 layer
+- **Lexical**: rename identifier (`x_a1b2c3`).
+- **Control flow**: opaque predicate, control-flow flattening.
+- **Data**: string encryption, constant unfolding.
+- **Anti-analysis**: anti-debug, VM detection, integrity check.
+- **Virtualization**: custom VM bytecode (VMProtect, Themida).
+
+### 매 trade-off
+- Performance: 2-10× slowdown (virtualization 시).
+- Size: 2-5× binary bloat.
+- Stability: false positive 가능 (anti-debug).
+- Security: 매 cost-raise 만 — break 시간을 hours → weeks 로.
+
+### 매 응용
+1. JavaScript bundle (anti-scraping).
+2. Mobile app DRM, license check.
+3. Game anti-cheat (e.g., VAC, EAC).
+4. Malware (defensive obfuscation).
+
+## 💻 패턴
+
+### String encryption
+```javascript
+// Before
+const KEY = "secret-api-key";
+
+// After
+const _0xa1b2 = ['c2VjcmV0', 'LWFwaQ==', 'LWtleQ=='];
+const _0xc3d4 = (i) => atob(_0xa1b2[i]);
+const KEY = _0xc3d4(0) + _0xc3d4(1) + _0xc3d4(2);
+```
+
+### Control-flow flattening
+```c
+// Before: linear flow
+void f() { a(); b(); c(); }
+
+// After: dispatcher loop
+void f_obf() {
+    int state = 0;
+    while (state != -1) {
+        switch (state) {
+            case 0: a(); state = 7; break;
+            case 7: b(); state = 3; break;
+            case 3: c(); state = -1; break;
+        }
+    }
+}
+```
+
+### Opaque predicate
+```cpp
+// Always true at runtime, hard to determine statically
+auto opaque = [](int x) { return (x*x*x - x) % 3 == 0; }; // always true for any int
+if (opaque(rand())) real_logic();
+else fake_branch();  // dead but appears live to disassembler
+```
+
+### Identifier mangling (terser)
+```javascript
+// terser config
+{
+  mangle: {
+    toplevel: true,
+    properties: { regex: /^_/ }
+  },
+  compress: { passes: 3, dead_code: true }
+}
+```
+
+### Anti-debug (browser)
+```javascript
+setInterval(() => {
+    const t = performance.now();
+    debugger;  // pauses if devtools open
+    if (performance.now() - t > 100) {
+        // devtools detected
+        location.href = 'about:blank';
+    }
+}, 1000);
+```
+
+### LLVM IR pass (obfuscator-llvm style)
+```cpp
+struct StringObfPass : PassInfoMixin<StringObfPass> {
+    PreservedAnalyses run(Module &M, ModuleAnalysisManager&) {
+        for (auto &GV : M.globals()) {
+            if (auto *CDA = dyn_cast<ConstantDataArray>(GV.getInitializer())) {
+                if (CDA->isString()) xor_encrypt(GV);
+            }
+        }
+        return PreservedAnalyses::none();
+    }
+};
+```
+
+## 매 결정 기준
+| 상황 | Approach |
+|---|---|
+| Web bundle anti-scraping | terser + javascript-obfuscator |
+| Native binary (commercial) | VMProtect / Themida |
+| Open-source w/ embedded secret | DON'T — use server-side proxy |
+| Game anti-cheat | Kernel driver + virtualization |
+| Mobile DRM | Hardware-backed (TEE, SEP) — obfuscation 보조 |
+
+**기본값**: Don't obfuscate — secrets belong server-side. Necessary 시 매 layered defense.
+
+## 🔗 Graph
+- 응용: [[Malware Analysis]]
+
+## 🤖 LLM 활용
+**언제**: Defense-in-depth context, malware analysis 학습, anti-tamper design.
+**언제 X**: Hiding actual secrets — broken by definition. 매 server-side 가 답.
+
+## ❌ 안티패턴
+- **Security through obscurity (alone)**: 매 always falls.
+- **Embedding API key in client**: obfuscation 으로도 매 보호 불가.
+- **Custom crypto**: roll-your-own → obfuscation 보다 매 weaker.
+- **Performance ignored**: 10× slowdown 으로 UX 망침.
+- **No update path**: 매 break 되면 매 fresh release 필요 — automation 필수.
+
+## 🧪 검증 / 중복
+- Verified (Collberg taxonomy, obfuscator-llvm, javascript-obfuscator).
+- 신뢰도 A.
+
+## 🕓 Changelog
+| 날짜 | 변경 |
+|---|---|
+| 2026-05-08 | Phase 1 |
+| 2026-05-10 | Manual cleanup — obfuscation taxonomy + JS/LLVM patterns |