201207211244 wwqrd

explained decrypted filler

seed 282

Metadata

Post ID: wwqrd
Title: 201207211244 → 2012-07-21 12:44 on A858's clock
Posted (UTC): 2012-07-21 03:41:56
Timezone: UTC+9 · title 12:44 against posted 03:41 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(A858DE45F56D9BC9A858DE45F56D9BC9) = 0dcc4bd9e114ebc42078977dc9125404 (name+name)
GUIDs: 21
Filler GUID seed: new Random(282).Next(9) ✓ verified
Run: Run 16 (seed 39,036,328) (seed)
Draw: 27 · predicted N = 21 ✓
Machine boot: 2012-07-11 17:05–17:10 (seed = uptime at app start)
Sources: community-archive, arctic-shift · body from community-archive
Links: Reddit · Arctic Shift · JSON
Score · comments: 5 · 0
Tags: automated (decryptable)2012Encrypted masked GUID listkey: name+namerun: 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 = A858DE45F56D9BC9A858DE45F56D9BC9 (name+name). Key = MD5(password) = 0dcc4bd9e114ebc42078977dc9125404, 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 80e30e53-ce54-09e5-b027-65b550264b14
  2 198ab9a0-e664-5106-bdc6-3f6c23db23b7
  3 d4e7d9af-740f-7216-8924-cb18174ad7ba
  4 d7dd752e-b1e7-66d3-a548-413d739cf584
  5 c8cfd751-6042-4e6c-be95-337b10a04b4c
  6 8b8cf6ba-4f3c-8325-9282-ce767464d7c9
  7 7a11f75c-3c55-2ef2-9a73-2581ee4b0056
  8 c2b45157-cd76-80d6-81c3-094c04bb073a
  9 57133f42-dd2a-7724-bcea-1e77367f50d7
 10 535881c0-a38a-2003-8f04-6047a1a2db49
 11 051cffba-a277-0dc0-8e36-9d1c23dad380
 12 1001c023-5edb-5a41-964e-4ab7b5f06757
 13 8ba54473-c4d2-4860-a342-d9e1147bde18
 14 59ea9e10-14ee-1e6e-b8b6-3d7126d39876
 15 e34a5c39-377f-37ab-969f-376c1dcdbc44
 16 6b53b02b-7994-1e4e-a7ce-0913a16fa665
 17 b882b421-7fb7-387b-ac9d-a01ddf16b9a4
 18 2451732d-4a92-7b28-96a3-a0bc68c961f6
 19 63e5ec0f-1362-2de3-b319-12f48864ea38
 20 e61f1df8-b3ad-4596-a135-abe84841c19c
 21 03bbd35a-a8ba-2e12-aaa7-243c9b530747

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 057648287205413137242. Exactly this sequence comes out of new Random(282).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 27 of Run 16 (seed 39,036,328): new Random(39036328), 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 2012-07-11 17:05–17:10).
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

Related