201206261139 vn4j2

explained decrypted filler

3DES(name) ECB, 17 GUIDs, seed 193

Metadata

Post ID: vn4j2
Title: 201206261139 → 2012-06-26 11:39 on A858's clock
Posted (UTC): 2012-06-26 18:38:08
Timezone: UTC−7 · title 11:39 against posted 18:38 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 1,104 hex characters · 552 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9) = 34a14a42e98ff96095af56604e290cae (name)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 17
Filler GUID seed: new Random(193).Next(9) ✓ verified
Run: Run 3 (seed 1,063,142,882) (seed)
Draw: 40 · predicted N = 17 ✓
Machine boot: 2012-06-14 10:25–10:26 (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: namerun: seed

From the post to its content

As posted (encrypted)

4D3BF885A0286AF7 D5CE7D665ACC08AA 18FC33848E5010D9 FBF8794866741775 6193DE124B95818E 84A327C8615B5BD8 E90BE420E8BA71A7 3207191FE4D6AFAB 607479058D1969F5 AFAF6AF40EFFCC62 495FC2D66C52F3FB C90C94EBF6993E86 4ED00A4F3B6A0309 B5C4E885C106FF69 B343FD9AD52E410B 72DFBF60607119B3 FDADBA1A94F5391C F8FF35888A8FF05F C55FE6DEB8F19000 1894C939A53DB486 2F129FE58901E3C3 35BDE643A92847F6 7BB243109D1D2710 EEB5C3CBDDC09443 C28D3B7E11C7F5CB BD75889F18610DA8 FC0EE2797EAEF755 056A5F1B030F137E 8E1C5EE333549045 FE4EAF20550E9260 DD87C99E72BE3CFE DA15BF078C6DCD2B 913A05951FFC0971 E4D1E4D6D973E85D FCD8C173353AB9FF CBD6DCE9A1205CE2 0C141E53520DA80D 331731F309859EBC C9F24BCCC70EBA48 200B9551E5D69A4E 7001AAAC78BEC2BF 01EC58C1EC5AF4B1 CDF4F152253843AD 7BC134AB5EDE7543 B0CAEC82CFEBD094 CF1BAFF1CB35CE8A 73E2D9CFB548ADF4 269748056AC0F0B2 7C3DCD81D18CA8AE 8BE6FC96927729D2 7ABA63C8DD163F18 D59AE51CB75B6998 7972DF05405FEA87 26FCE11D6B25AEDC 11564EF8FEC94CAC C1F2DB7F8E2F274A 5E059239814BE799 BEA4643E637EC3B9 FE1DAAC1D4F10E7A BD4571FB8F79A022 95B1F2D9FE6D4F41 1C3C073B8451BB8C 68D66812FB5541D2 1E4721236C86253B 25635D4ABD0017BD ABA52474CC0E4747 A4EA7EC484ECED46 09B99646A35387C7 5DACFFBA8FF64DBD

Read the ciphertext. Strip whitespace: 1,104 hex characters = 552 bytes = 69 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9 (name). Key = MD5(password) = 34a14a42e98ff96095af56604e290cae, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 17 GUIDs as hex (shown below).

Decrypted: GUID list

  1 80386eba-1d40-46a3-8f4c-a81f288511eb
  2 cf11852f-7f6e-4c80-8a07-8097e629712f
  3 993651f4-2fea-6403-89ce-7e80a8ac6ccf
  4 eb14a309-53e0-6743-b546-fe866b5152a5
  5 b5f90506-4c30-3c69-8564-0c63d9cd8427
  6 0435a36b-4c8d-1c65-a577-171463178e27
  7 3d9156b6-889a-3637-8e00-fa41f59902dd
  8 480e2658-dc8e-253a-a182-a5bcac2f6ff9
  9 9c26f157-f67b-7b1d-8ea5-3e26104b02d1
 10 b3e6dcde-00dd-3775-812b-3b7377fe4327
 11 b15ad3e3-9ebb-4589-8b75-d74c4648a9b3
 12 6d623b16-d39d-1c87-9d8b-0e6f87572ca4
 13 d8a82b78-d1b0-2c6f-ac4d-4a5ae6bd2b48
 14 a1547242-d264-7ad1-ba02-aa4f6611a00f
 15 6da845de-caa1-071b-b2ee-7c4eaa02e77d
 16 fb7dbbe8-bd31-5417-9a6b-594c75a523c3
 17 dfc85f40-3f7c-80ca-9ecc-f731ff3c4b03

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 44663132734127058. Exactly this sequence comes out of new Random(193).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 40 of Run 3 (seed 1,063,142,882): new Random(1063142882), Next(8,24) per post. The RNG predicts N = 17; the post has N = 17 ✓. The seed is the machine's uptime in ms when the app started (boot 2012-06-14 10:25–10:26).
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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