201209010726 z5q6j

explained decrypted filler

3DES(name+title) ECB, 20 GUIDs, seed 651

Metadata

Post ID: z5q6j
Title: 201209010726 → 2012-09-01 07:26 on A858's clock
Posted (UTC): 2012-08-31 22:26:06
Timezone: UTC+9 · title 07:26 against posted 22:26 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 1,296 hex characters · 648 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9201209010726) = 7e57bd269f7d8b66cd412f0092a08f72 (name+title)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 20
Filler GUID seed: new Random(651).Next(9) ✓ verified
Run: Run 27 (seed 1,337,299,625) (seed)
Draw: 25 · predicted N = 20 ✓
Machine boot: 2012-08-15 10:07–10:24 (seed = uptime at app start)
Sources: arctic-shift · body from arctic-shift
Links: Reddit · Arctic Shift · JSON
Score · comments: 5 · 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: 1,296 hex characters = 648 bytes = 81 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201209010726 (name+title). Key = MD5(password) = 7e57bd269f7d8b66cd412f0092a08f72, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 20 GUIDs as hex (shown below).

Decrypted: GUID list

  1 9eab05e1-2659-771f-bae5-7c7452657586
  2 e4a95232-c259-77cc-aad5-6cca6f2015ac
  3 9d4a0c6d-a770-7fe7-86da-c2246fab1a90
  4 e945911d-87d9-4745-98fb-11dacf1092bd
  5 28a566f0-168e-1b11-a541-4ab8d19dfba4
  6 1d9eaf07-3d6f-4065-b7c3-5f0766e72fe7
  7 aa34da62-2f1b-55bd-87f4-10f9fc1fe894
  8 d81a0e43-493b-041f-bbdc-6509ba843b91
  9 235ac1a8-c726-4c0b-bbd0-1a85fc6ef913
 10 0423e697-9b3f-2b10-84b4-5d9c2f76ced8
 11 28409056-a380-80dc-a4e5-be3e33a7872a
 12 773cd087-f410-66e3-b0b0-f2fe43b35418
 13 158e9337-ba37-1b3b-8261-82f4e9bbee72
 14 4eb26e9c-ab1a-149a-98a9-88eee84873b7
 15 2e644ced-10cf-51a1-9814-9cab5aac6903
 16 5c260bee-3934-52e4-8db4-defae31db877
 17 a3e4e853-8d07-4de3-b213-6e8d33829ab5
 18 dc4870ed-7d48-58b5-a719-4861d74112ee
 19 e4149f7a-dca1-23a7-979e-055a5d3dfc0f
 20 a5575844-d992-319b-b3f6-6d2a8b482955

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 77741450428611554523. Exactly this sequence comes out of new Random(651).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 25 of Run 27 (seed 1,337,299,625): new Random(1337299625), Next(8,64) per post. The RNG predicts N = 20; the post has N = 20 ✓. The seed is the machine's uptime in ms when the app started (boot 2012-08-15 10:07–10:24).
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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