201210190600 11pkup

explained decrypted filler

3DES(name+title) ECB, 21 GUIDs, seed 884

Metadata

Post ID: 11pkup
Title: 201210190600 → 2012-10-19 06:00 on A858's clock
Posted (UTC): 2012-10-18 21:00:04
Timezone: UTC+9 · title 06:00 against posted 21:00 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 1,360 hex characters · 680 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9201210190600) = fb6335405ca432a215e0518a2ce29e26 (name+title)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 21
Filler GUID seed: new Random(884).Next(9) ✓ verified
Run: Run 37 (seed 425,468,968) (seed)
Draw: 9 · predicted N = 21 ✓
Machine boot: 2012-10-10 14:48–22:48 (seed = uptime at app start)
Sources: arctic-shift · body from arctic-shift
Links: Reddit · Arctic Shift · JSON
Score · comments: 1 · 0
Tags: automated (decryptable)2012Encrypted masked GUID listarctic-onlykey: name+titlerun: seed

From the post to its content

As posted (encrypted)

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

Read the ciphertext. Strip whitespace: 1,360 hex characters = 680 bytes = 85 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201210190600 (name+title). Key = MD5(password) = fb6335405ca432a215e0518a2ce29e26, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 21 GUIDs as hex (shown below).

Decrypted: GUID list

  1 0ab185e6-33e2-403c-b2d1-fede06a5503d
  2 b6bd3459-cba8-1a17-9f85-af4de560ef13
  3 51e9eee3-e81c-6edd-99c8-a4c1c71533e2
  4 57f3d221-cca7-2314-8d2e-bd12f2a965a5
  5 88f67d22-8668-214a-b736-a74422a43d8a
  6 2b94d884-61c4-01e1-9d7f-ae50e873b4c1
  7 61b9e1a0-5f81-8441-826b-421e4c4f2f93
  8 16589a4a-efe6-82bb-907f-de8e258110d3
  9 20b02e7d-c0f6-340e-97b4-47c7e9a49a8c
 10 f4e924ee-a25c-2d01-846b-ef2f130f6d59
 11 571a12e4-1154-55c0-bde4-14a5e980f0c8
 12 5274404e-a632-572f-b316-3c1aa5266637
 13 575dd0b1-ffe0-36d7-9d31-a5b0c3f264e1
 14 51c529ec-a001-39e4-bd20-0298ffbcd39f
 15 6a77224c-ae98-62b9-88ee-7f9b12e6c6fc
 16 c9c1d7e7-af27-011f-ab62-5e1b4a4d16fb
 17 7ad65864-24d0-4eae-986b-e04f62aaca11
 18 5da1571e-6a3f-04b8-b16f-83d6c5cb477c
 19 a49e33ab-8c3a-5e92-952f-e2855ac04005
 20 9fb94bc8-9648-5abb-9c5e-92acf506333f
 21 307ab0a4-d8f5-2004-8f4c-138b7837e527

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 416220883255336040552. Exactly this sequence comes out of new Random(884).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 9 of Run 37 (seed 425,468,968): new Random(425468968), Next(8,64) per post. The RNG predicts N = 21; the post has N = 21 ✓. The seed is the machine's uptime in ms when the app started (boot 2012-10-10 14:48–22:48).
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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