201210071925 113yhu

explained decrypted filler

3DES(name+title) ECB, 22 GUIDs, seed 921

Metadata

Post ID: 113yhu
Title: 201210071925 → 2012-10-07 19:25 on A858's clock
Posted (UTC): 2012-10-07 23:25:30
Timezone: UTC−4 · title 19:25 against posted 23:25 UTC
Author: [deleted]
Account: A858DE45F56D9BC9 main account
Subreddit: r/A858DE45F56D9BC9 the main subreddit
Category: F3 filler: 3DES(name/title) → GUID list, seed known
Size: 1,424 hex characters · 712 bytes
Cipher: 3DES-EDE2 (two-key Triple DES), ECB, PKCS7
Key: MD5(A858DE45F56D9BC9201210071925) = 7adac3cbf1d2fd68a8f8147af2d85848 (name+title)
New here: Missing from the community archive; decrypted here for the first time. (new results)
GUIDs: 22
Filler GUID seed: new Random(921).Next(9) ✓ verified
Run: Run 35 (seed 854,622,578) (seed)
Draw: 406 · predicted N = 22 ✓
Machine boot: 2012-09-22 10:16–10:36 (seed = uptime at app start)
Sources: arctic-shift · body from arctic-shift
Links: Reddit · Arctic Shift · JSON
Score · comments: 2 · 0
Tags: automated (decryptable)2012Encrypted masked GUID listarctic-onlykey: name+titlerun: seed

From the post to its content

As posted (encrypted)

36902ADD30D63046 BBBAE89542E1EA54 593587CF62559984 1575C966730C574D 5FFE24CDE8F95ACD D2DB4215E18AE55D 81F443FE64520E93 16EC144C8A5E1323 9FB94AAF084FD8C7 4F8C22A9A3BDBC12 49E10BA139D0B3DD 5105033A561D55CC 7CA3F61B2C77B879 C93FB4A8AD327BC5 8E54C435D70B0534 FDD7237E3776CF02 FC30A83265C1DFCF 770C52F657B67481 7B841714A7EC6B17 19541FE44A946EA0 85B0225598B2E167 9E938FECECDF6B99 2041E5BB163A3D2B FCE44BD234FDF0B3 81B71F5526F8D214 216FC34F6C100850 5629FF793A805534 737642E06F850759 427C1231DAAD6E9D 7B472986BB277428 2C9D7A8056C6FC0E 60667AEFD5E43FF8 B8AC0C10B8012F34 BA365A368555A5E3 FECAE651AB281BA7 B727AB98BEC3DD47 DCEB5021AF533088 22261B9FA78F9165 28686315868236AA 7441F246011B9C04 0C277676423ECBB9 F364DBB7B970B111 9FE7DD3809CA4889 909F32906D440CF5 8FBA255DE2598218 C97411AA837537E1 A1DDB9AB894105C3 C6A4B52E19FB2413 0A9C72CDD01BC8A0 7A7823E2F8CF1AED 7444715CF33BD947 AA09879B7539EFEB 5E663A994680676E 8BDA9351C5212177 8B4C6B5032354857 50EAF74995508D44 1D9687DCA2A88832 F7495D1E4355686A 01AAC896B724D3B3 09D71904D2BFD057 8B936AE8D9CCCA19 D1D0F5288695B894 A941D4B98B84DA4F C702A723BEC8F2B5 2EF49E1A872C9E38 489485F578794152 7F973B028F737542 3F065E4EE59C14AE 80D18C16C89700A8 EEF20E9C37B8BA47 5C60E706CED58F98 0E218567E8B4CE6F 56349B32C7CD1951 3F0A9B7546346EE5 6E4666D451E85495 C362FD8C27455498 A926E2815EE7F50D C63608DAA70C3697 FF46A773E1E1963E A0D9BB75163B1A7B F53769320AAA3FB8 2FEA5438B57C6DE9 D43229925CCA504B B209B13A1F4D30CD A9EC4BB040071936 DDC6447D32791C16 2AD45912A293C319 613DEA558A35404D 249167542574D940

Read the ciphertext. Strip whitespace: 1,424 hex characters = 712 bytes = 89 8-byte 3DES blocks.
Derive the key. Password = A858DE45F56D9BC9201210071925 (name+title). Key = MD5(password) = 7adac3cbf1d2fd68a8f8147af2d85848, used as a two-key 3DES key.
Decrypt. 3DES-EDE2 in ECB mode, then strip the PKCS7 padding. The plaintext is 22 GUIDs as hex (shown below).

Decrypted: GUID list

  1 704db82b-d640-7312-a498-cf9506fc04f2
  2 9d4da6a8-8f5a-0f66-8d13-0e839efc685d
  3 5bf86e2f-b305-4d49-865a-a2841239db08
  4 58ce631b-3f48-1cdf-8575-7712e1c84884
  5 5812b219-27b1-099c-ba41-dc34e90777e4
  6 b38c5fc1-6057-3770-a3be-4a2c3fe7a97d
  7 7d5e5fad-4f9f-516f-b5f8-0bcd7617f850
  8 71fb1908-00a8-4508-a408-ce1a4a258a32
  9 74b7e4b0-9ac1-861b-b6b9-7c352e416ec4
 10 76e20205-2b28-8cdf-857d-dd1bd5eb14f7
 11 37533022-46ea-7ceb-90de-0615c9fc9e10
 12 eb1ff3e5-dcf6-4f22-83aa-d7ca6cc941fa
 13 fcbfb04f-3458-6ad7-960d-c0bc6c03fa46
 14 702f031c-72e3-57c9-bb68-52143e025aa4
 15 e4fdd5a0-3a54-5734-a0e9-9188c161f4c5
 16 d4232975-482f-1268-b1e2-deb90473fe61
 17 a05ff9d7-6ed2-0904-95da-d98e5e3f4398
 18 3468436a-5c26-0c3f-a21a-6e475276b620
 19 1d751136-a5f4-5d1c-aba6-d3e80c46b6e7
 20 ff75d7c0-e760-82a4-9fab-988312dd8d92
 21 1558877e-2d04-18aa-a261-14a470d558f1
 22 be5022b5-edca-766a-888d-bd74426b714e

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 7041035488746551005817. Exactly this sequence comes out of new Random(921).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 406 of Run 35 (seed 854,622,578): new Random(854622578), Next(8,64) per post. The RNG predicts N = 22; the post has N = 22 ✓. The seed is the machine's uptime in ms when the app started (boot 2012-09-22 10:16–10:36).
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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