201209232110 10c7np

explained decrypted filler

3DES(name+title) ECB, 28 GUIDs, seed 100

Metadata

Post ID: 10c7np
Title: 201209232110 → 2012-09-23 21:10 on A858's clock
Posted (UTC): 2012-09-23 12:10:07
Timezone: UTC+9 · title 21:10 against posted 12:10 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 1,808 hex characters · 904 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9201209232110) = e0f5bf011f16277f9e939d27d6159996 (name+title)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 28
Filler GUID seed: new Random(100).Next(9) ✓ verified
Run: Run 34 (seed 83,105,000) (seed)
Draw: 8 · predicted N = 28 ✓
Machine boot: 2012-09-22 10:23–10:24 (seed = uptime at app start)
Sources: arctic-shift · body from arctic-shift
Links: Reddit · Arctic Shift · JSON
Score · comments: 5 · 1
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: 1,808 hex characters = 904 bytes = 113 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201209232110 (name+title). Key = MD5(password) = e0f5bf011f16277f9e939d27d6159996, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 28 GUIDs as hex (shown below).

Decrypted: GUID list

  1 dd0aac67-c90f-8259-a1db-2f328d0598ef
  2 56fcc2f4-37ae-16b5-9a1e-ba17b2eb2ac1
  3 2ae603fb-7884-6b78-8c52-411154d2b374
  4 c95b1d1e-7cb3-8087-aadd-5ef4a74da443
  5 224dcb1a-dc73-398c-a630-bbe1eb3c0120
  6 772a3290-216d-8910-9278-ddc6c325d709
  7 c4c3b827-e105-6be0-8c62-cf9482ab3468
  8 f72dca09-5db6-5917-ad95-bcec440c6f41
  9 41b93bb3-8afd-3d9b-b73f-4e4ee0bf8155
 10 1da40b3c-0435-17f8-942d-fe24bcbdaeaa
 11 0b258555-77ed-8d86-9ecd-2f7708a5db54
 12 71350a60-4ba6-466e-877e-1a107c359538
 13 c0bb5afc-aef9-3049-986c-49f7a83595ad
 14 9c32b556-1ccf-4b24-a285-6787640fe34f
 15 0298c7d7-a96c-8982-87ff-5ac72b3272f9
 16 a5c31d3c-6e55-40f1-ba78-57bf07d80890
 17 02daa6d4-2daf-85f9-a386-25d0432b004f
 18 112c07ae-81a9-8fdc-90bc-91e14842a99a
 19 aa6d373f-14a7-3d8d-9772-04483c9ce47b
 20 9de6565f-4168-04e6-acdc-a009f44e514b
 21 b8a8e0a2-8a64-064a-8c81-5ba65df5cde7
 22 a10fd8ac-ac9d-398d-b9cc-5cc220b9beed
 23 6420b625-0897-8f77-85e1-d9ea5b090ccf
 24 ae7d5b1f-b32f-88df-a55e-eb9f70ae917c
 25 caddd07b-9261-4848-bcd4-e93fbb00cad4
 26 1a920707-f8b2-700e-a6be-d61bb28049dd
 27 dad1d849-c23c-8d75-a99a-6a1acdc9c71c
 28 229dbeca-4542-59f6-9f40-3586e69722df

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 8168386531843484883003884785. Exactly this sequence comes out of new Random(100).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 8 of Run 34 (seed 83,105,000): new Random(83105000), Next(8,64) per post. The RNG predicts N = 28; the post has N = 28 ✓. The seed is the machine's uptime in ms when the app started (boot 2012-09-22 10:23–10:24).
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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