{
 "id": "3j99nf",
 "title": "201509011522",
 "title_time": "2015-09-01T15:22",
 "author": "[deleted]",
 "account": "A858DE45F56D9BC9",
 "subreddit": "A858DE45F56D9BC9",
 "created_utc": "2015-09-01T19:22:00Z",
 "permalink": "https://www.reddit.com/r/A858DE45F56D9BC9/comments/3j99nf/201509011522/",
 "arctic_shift": "https://arctic-shift.photon-reddit.com/api/posts/ids?ids=3j99nf",
 "sources": [
  "community-archive",
  "arctic-shift"
 ],
 "body": "c8ca968583244e3d 52b0218d0905cd2a 91ad308faca568e2 9ed4da07730c16d7 52d00de5130de58a bd605b631fd51c6a bcedef9fe505190b a941d0fa18b1c81e 55c6dd1d54a38bb0 ",
 "body_source": "community-archive",
 "body_other_version": "[deleted]",
 "body_hex_chars": 144,
 "bytes": 72,
 "score": 10,
 "num_comments": 56,
 "category": {
  "code": "S",
  "label": "S solved 3DES → text"
 },
 "kind": "manual",
 "encryption": "decrypted",
 "status": "solved",
 "summary": "'The treasure is amoung the trash.' 3DES-CBC, key MD5(name), first block lost.",
 "content_type": [
  "Operational notes"
 ],
 "cipher": {
  "algorithm": "3DES-EDE2 (two-key Triple DES)",
  "mode": "CBC",
  "padding": "PKCS7",
  "key_derivation": "MD5(password)",
  "password_recipe": "name",
  "password": "A858DE45F56D9BC9",
  "key_hex": "34a14a42e98ff96095af56604e290cae",
  "iv": {
   "status": "presumed",
   "value": "793CB9632695D67F",
   "first_block": "54686520"
  },
  "steps": [
   [
    "Derive the key",
    "Password = <code>A858DE45F56D9BC9</code> (name); key = MD5(password) = <code>34a14a42e98ff96095af56604e290cae</code>, used as a two-key 3DES key."
   ],
   [
    "Decrypt",
    "3DES-EDE2 in <em>CBC</em> mode, then strip the PKCS7 padding."
   ],
   [
    "Presumed IV",
    "The IV was never published. Assuming the first 8 bytes are the hex of \"The \" (the text below is hex-encoded), the IV is D(C0) XOR that block = <code>793CB9632695D67F</code>. A presumed value, not a recovered one: every block after the first decrypts the same way whatever the IV is."
   ],
   [
    "Decode",
    "The text is hex-encoded: each pair of characters is one byte, and decoding it gives the text shown below."
   ]
  ],
  "raw": "54686520747265617375726520697320616D6F756E67207468652074726173682E",
  "layers": [
   {
    "encoding": "hex",
    "text": "The treasure is amoung the trash."
   }
  ],
  "presumed_prefix": "The "
 },
 "plaintext": "The treasure is amoung the trash.",
 "word_layer": null,
 "credit": null,
 "decoded_layers": null,
 "guids": null,
 "count_from_length": null,
 "run": null,
 "known_solution": [
  {
   "Method": "3DES-CBC, key MD5(name), IV not recovered; plaintext is hex-ASCII",
   "Result": "'The treasure is amoung the trash.'",
   "Explanation": "First block lost; wiki documents the same key, mode and text; verifier checks the decoded blocks 1..",
   "Re-checked": "3DES-CBC MD5(name), IV lost: hex-ASCII text, post `3j99nf`"
  }
 ],
 "tags": [
  "post-cutover",
  "2015",
  "Solved special post",
  "manual",
  "edited",
  "key: name",
  "operational notes"
 ],
 "title_zone_hours": -4,
 "title_zone": "UTC−4",
 "page": "posts/3j99nf/"
}