201210040542 10xg0v

explained decrypted filler

3DES(name+title) ECB, 15 GUIDs, seed 652

Metadata

Post ID: 10xg0v
Title: 201210040542 → 2012-10-04 05:42 on A858's clock
Posted (UTC): 2012-10-04 09:42:05
Timezone: UTC−4 · title 05:42 against posted 09:42 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 976 hex characters · 488 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9201210040542) = 926b74541b81165ec1a26fbdbb0bee01 (name+title)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 15
Filler GUID seed: new Random(652).Next(9) ✓ verified
Run: Run 35 (seed 854,622,578) (seed)
Draw: 149 · predicted N = 15 ✓
Machine boot: 2012-09-22 10:16–10:36 (seed = uptime at app start)
Sources: arctic-shift · body from arctic-shift
Links: Reddit · Arctic Shift · JSON
Score · comments: 3 · 0
Tags: automated (decryptable)2012Encrypted masked GUID listarctic-onlykey: name+titlerun: seed

From the post to its content

As posted (encrypted)

8121CFE13B98BDF3 B31BA3E9B1886406 14148663A135FBE3 27F098495474B30D 4C24EEC19F162DC3 48ABEBDD2437BE64 248DD07C5893DCCD D03FC12150F12403 736EF383AF7FDE90 69AD1BD3BB795447 138798269EDA50D1 0437293CADF22E6D 83031F2679964519 5707E72CEDDADDE0 B43AFF20291DD353 4C9625B099768EF3 11BA504B791B6604 44B86CA4A0E97DC8 B424D50B93F37B0E B027DDEAEA30392A 41CABCAB35537A47 9705D3877FAA4C1F 3C79FCF825019487 B99A8F9DD4A00342 CB2513AFD3C9536D 176CBE6F9099A406 AA3AEB9D044B95E5 DA780171F2BB956B 88857995EECA92B8 2E4CBDD8A2BF9F3B 1458722384348742 1D0AA0239154B5BC 932D3CD7222EC16A 68446AD4FD14C535 E76D71B0FF9B8E52 B3E117DDD77E2D6B 36F5F024F9756CD1 9C7A1865209148B9 D87E78886E3E9F03 465AF3F5E8234E35 291C48CF15FC6BD0 F2A9515D86CAD797 C2BF0D6A8680D6F7 0768CFEDD773A65E F8F8BF74411207A3 F72D69A8E857F240 8187A8EEF1FC01D0 0CA42F257CC03F86 FF1AC694553491D9 2C2FE56AFB6810B2 22155839717DC3C5 20490BBEE5DA8BB5 7E4CBACC1169FA15 7BF79782746C872D 8CF5C10F00FF5DC5 547C0E3DAE2AF47D AAC4AC803C330A63 7FF778342867B7FC 47F1A15F9D76C723 DD05530BCD939014 3A837E40E7A90BFF

Read the ciphertext. Strip whitespace: 976 hex characters = 488 bytes = 61 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201210040542 (name+title). Key = MD5(password) = 926b74541b81165ec1a26fbdbb0bee01, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 15 GUIDs as hex (shown below).

Decrypted: GUID list

  1 956812a8-4349-30f9-9add-787506532cba
  2 79175bf6-ef0b-1dd3-a19e-8e8607204661
  3 0ae7667c-8cae-40ec-a7e1-20c6178e928b
  4 1d3bf3a2-722b-6519-8a36-a94a18979e16
  5 0f8d40df-5a57-50c5-89f2-398cfb948566
  6 f90a4aba-7dcf-3119-86a2-3f17b4c0d796
  7 554d4d20-bb1b-08c2-9d97-59946eca9ee1
  8 8280b97e-33e0-4243-afe9-7e941e80ce25
  9 f68a8d75-2cb3-528a-9dc8-1c8971359baf
 10 4f16d571-229d-6bd0-a12f-60e76043cfd6
 11 cbf5456e-4933-5cfe-970e-96f50517c61d
 12 02295a7a-9f34-46f3-b8bf-a0442fc384c1
 13 49396bd5-7e9a-7b4a-beed-405560eba4b4
 14 39c69c6c-7fb6-6f6e-9e8b-0f9f42e32ef2
 15 10714e3e-0b48-302f-b179-a711deb1f511

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 314653045654763. Exactly this sequence comes out of new Random(652).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 149 of Run 35 (seed 854,622,578): new Random(854622578), Next(8,64) per post. The RNG predicts N = 15; the post has N = 15 ✓. The seed is the machine's uptime in ms when the app started (boot 2012-09-22 10:16–10:36).
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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