201212031708 1482nd

explained decrypted filler

seed 378

Metadata

Post ID: 1482nd
Title: 201212031708 → 2012-12-03 17:08 on A858's clock
Posted (UTC): 2012-12-03 22:08:04
Timezone: UTC−5 · title 17:08 against posted 22:08 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 1,488 hex characters · 744 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9201212031708) = f4cc0fc556c162fe77e9db011b601a57 (name+title)
GUIDs: 23
Filler GUID seed: new Random(378).Next(9) ✓ verified
Run: Run 39 (seed 1,106,402,812) (seed)
Draw: 5 · predicted N = 23 ✓
Machine boot: 2012-11-20 22:02–00:02 (seed = uptime at app start)
Sources: community-archive, arctic-shift · body from community-archive
Links: Reddit · Arctic Shift · JSON
Score · comments: 1 · 1
Tags: automated (decryptable)2012Encrypted masked GUID listkey: name+titlerun: seed

From the post to its content

As posted (encrypted)

8DB036755DC62336 64827928CA3E7388 FDBB4019C120584A EA303A415E432819 4F0BB7ADEBEA36D2 F2239ECD00C2F1FB 4039006496776732 7D47D9A5E6F2414B 52FA048180BECF40 9AB7FEEC1262B4DF 3873DECD70369D07 3C962F311710CEF8 2777B8CD916829DA 9F9B271AC3389318 732F68FEC46AA135 4FDECB36A70BE811 DC031A5D97A762FD A009105638DC5545 96C416A368928091 F3780A9EC7FABB11 E4B70DB72CDF5A27 F1F505E5E6E49BB0 86B43244CE64CF4C 9AE5D2041CA6F6C4 692046D6E708E5C4 BE13DB6C1031A09A 1A130DC98AB1242C 6194D6B998DBEE68 987A368C0CB27F2B DD8523AC585CF8C8 9CD2DACDE7FE62BA E3C9ABD6CFC8C277 476865C6F99D0D0C 7A72AD73BCCCB025 D5BE79C61C901F8F 7E8EC1423B0552B1 97A56B8DABA02E1A 99C18151E189823E 0A1C604499BA69C5 A2099543093C7518 9944E8184FCA3D84 CB5BB4AB9E8C3BE7 B5989FCE539ACCD7 7257C96513F51210 0C87C7079EE41D79 95EDE5D36B721C04 0F72119508D027C3 1D76564D27E9E2AE 41DFD78AF0FB6E25 43FE17427A6C12F9 CD9C92F3DA4C8755 F008797319A19DFE 8B6DDCBFDA106CA3 4FAC95BDEE07C803 BD34C4C9BEC12986 92AB005A8072A497 9BBD0548AD0ACA07 25A5DF0CB6D73CFE 0DC1B344F09F3ED2 3422BA67A87D19C0 E0BA1089E03B0863 791E1BFC962AD5E2 541D50F5FE4E17B3 C9BEFCCFF574346C FB6144BBAD798146 C2DF96D199848512 97961BB9B8DDD5D3 E93CF803574566DE C7E27EB842A4E35B D607871812AD851B F3B3ABD85F82B99E C9EA9EF846D2CD3E DC187954A6C89E38 547BD784EB4EDE14 F1903B111DD5AA8A EBD1B5C4473DB71B 1D7268EB27517176 F3C7A0BDC4BE194F 7EFEFD03DD13E3FF 8A8B2C4D9D946056 1E63242DA9C7FEA2 2EB8F184139D4F47 718F2505DF14F943 A274A1746A993E89 B6CB2F06B3886AA2 6ED65E81F706CC45 9D8663900873CC4A DA74792CF43973DB D4D13ACEA3A0C201 884A75216864800F 7292426FEC76B399 3E5645D1825D2C8E 7C9D55FA1AB2D9E2

Read the ciphertext. Strip whitespace: 1,488 hex characters = 744 bytes = 93 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201212031708 (name+title). Key = MD5(password) = f4cc0fc556c162fe77e9db011b601a57, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 23 GUIDs as hex (shown below).

Decrypted: GUID list

  1 211de6a5-4766-133a-b02d-197263879bf0
  2 ab0383d3-a6ab-65e3-9f4c-83b2f36f97cd
  3 519c251e-c480-8144-b505-38cb2a6b5459
  4 0ea5b112-2baf-2a29-8f88-35d1240823f3
  5 e0c03995-9a75-7308-b14f-46856af09bd7
  6 e4b43113-eff8-850a-b0b0-f84a402645d3
  7 13f9e677-1ca1-22a2-a9f6-e3619f208f80
  8 2caeff8b-a34f-003d-a3b4-303e07d393b5
  9 7c7ddf42-c81b-6a90-830b-12dba80d0ed0
 10 e73a4ad0-3cf2-5a14-8a07-1ffebace8687
 11 ae3c77de-d65d-6fb8-a00a-3e4d4e2de0b9
 12 a48bf61f-2057-59c9-9234-2e59ae938107
 13 9629a963-3236-4a08-b07b-35abcf4ef72c
 14 edea6593-1423-1fe8-8d19-dd04a1e9c465
 15 a16d2d1b-aa97-5c71-8719-ca926374e724
 16 d52f3aeb-0abe-02f1-8db4-67e14411cc5c
 17 1fe108f8-6515-6daf-ab4f-26e603c322ed
 18 887631a1-6303-3e04-84a2-46b3116928ce
 19 3c336e90-ea7c-81c0-aec7-3858bb3e0a50
 20 b9d6241d-caa3-6ca8-b71c-12ccba8c726a
 21 e7b851b9-cb4a-02df-a0d2-4aaffe2d77ec
 22 6022ecdf-073c-5365-963d-33fd6780ebc6
 23 930fdf55-3c91-7ee5-8d4b-54bfbe4f075b

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 16827820656541506386057. Exactly this sequence comes out of new Random(378).Next(9): the per-post millisecond seed of the mask generator. The other 30 hex digits of each GUID are Guid.NewGuid() output and carry no message.
Explain the count. This post is draw 5 of Run 39 (seed 1,106,402,812): new Random(1106402812), Next(8,64) per post. The RNG predicts N = 23; the post has N = 23 ✓. The seed is the machine's uptime in ms when the app started (boot 2012-11-20 22:02–00:02).
Conclusion. Filler. The content is fully explained by the two RNGs.

Metadata

From the post to its content

As posted (encrypted)

Decrypted: GUID list

Explanation

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