{
  "added_at": "2026-11-09",
  "category": "reconstruction-cases",
  "class": "software",
  "description_en": "ndec-re investigates an old MS-DOS COM encryption program through debugger-assisted assembly analysis and implements its encryption behavior in Go. The write-up traces the program's copied code, password-derived gamma and hashes, self-modifying instruction choice, initialization byte and mixing rounds. The repository also contains the original COM file and Go tests.",
  "description_zh": "ndec-re 借助调试器和汇编分析研究一款旧式 MS-DOS COM 加密程序，并用 Go 实现其加密行为。研究记录追踪代码搬移、口令生成的序列与哈希、自修改指令选择、初始化字节及混合轮次；仓库还包含原始 COM 文件和 Go 测试。",
  "entry_url": "https://awesomerea.org/resources/ndec-re-case/",
  "entry_url_zh": "https://awesomerea.org/zh/resources/ndec-re-case/",
  "evidence_url": "https://github.com/bereal/ndec-re/blob/12ae44a128fb14dd2c4453a3b2dbe08b336f7cc7/README.md",
  "group": "cases",
  "id": "ndec-re-case",
  "json_url": "https://awesomerea.org/resources/ndec-re-case/record.json",
  "kind": "case-study",
  "markdown_url": "https://awesomerea.org/resources/ndec-re-case/index.md",
  "markdown_url_zh": "https://awesomerea.org/zh/resources/ndec-re-case/index.md",
  "name": "ndec-re: reconstructing an MS-DOS encryption program",
  "name_zh": "ndec-re：还原一款 MS-DOS 加密程序",
  "record_type": "resource",
  "relationship": "independent-reconstruction",
  "requirement_facets": [
    "prerequisites",
    "limits",
    "license"
  ],
  "requirements": [
    "Go 1.21 is declared in go.mod for the reimplementation.",
    "The author leaves parts of the unpacking and exact algorithm marked for further work.",
    "No licence file in the repository."
  ],
  "requirements_zh": [
    "Go 实现在 go.mod 中声明使用 Go 1.21。",
    "作者将部分解包过程及算法细节标为待继续研究。",
    "仓库中没有许可证文件。"
  ],
  "targets": [
    "binary"
  ],
  "url": "https://github.com/bereal/ndec-re",
  "verification": "source-reviewed",
  "verified_at": "2026-11-07"
}