201206261106 vn27t

explained decrypted filler

3DES(name) ECB, 17 GUIDs, seed 963

Metadata

Post ID: vn27t
Title: 201206261106 → 2012-06-26 11:06 on A858's clock
Posted (UTC): 2012-06-26 18:04:33
Timezone: UTC−7 · title 11:06 against posted 18:04 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(963).Next(9) ✓ verified
Run: Run 3 (seed 1,063,142,882) (seed)
Draw: 15 · 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: 5 · 0
Tags: automated (decryptable)2012Encrypted masked GUID listarctic-onlykey: namerun: seed

From the post to its content

As posted (encrypted)

9516B44219E00B9A CCB90670F25545DA 5C7BC9348AAF0A4A E65B8AA35873607E 94BB91C57ACC20EE B3A205440AE0C163 241DB0B3224973C1 4641F70B43F58C81 B5B4BC9335692EE6 A66E3B48B2B1F377 E7F3BA18A31B8D57 5C37076294D588D8 26E82FAD0F90B85E 478203E7371AE318 E9A2C855B031EE9B D8933531E64DABA2 341C69C3E3F4F524 D0F1EC0BB8EE878E 444D18CD46E3153C 875E17B173017FFD 7ACC130B3AA71FA2 1DD7F1C8F9266887 41A43D10811DB963 74A8394445F59573 28845E5DADE02173 B55AA08012A9C9F1 4F33A70A084F231B 9919B893C3F1C014 4BC791368896DAF7 E337D1368C0CE843 3A438BB70558E1CC E2F028F1A31E1B97 5A205C12E6B22C2D 0AE529DB02E74654 F6EA5CC4BFFEFBDD 272EEF2F6280A288 C3F837CC5C834F4F DFA37102D41AD335 D23821AC6E2CF8D1 7B193A29040F2390 FD66AFFB858BE5F3 84D739570DA473AE DA9AE52ABF367C04 A59DD759C548CDFB 6ABCACB7536EB7CB AA51EE2D4AB79500 6CF7E0F935036BB8 9B9899944DAE4783 AF88B40034F1C1ED 6E7916699ADECE91 9BA20A260CF8EA8F 32A6E690972E28BD 576ECC64614BB768 99A2A73F599019CB 670D53C6D52A40B3 8D0BDF4AAE7378C2 D997DF28602F64E5 D49B4E4B8B0FDA3C 577A08E79A588CFE B47E8D90C63B2565 FE9AA987B397D0C9 66A1E5BA6B2FE0B6 1FE3B311F7274042 7BBD478D16B66957 ED69C9E2EAE7FCF9 1629AF0CB7F3D540 163436749E67E497 6018C8444D683580 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 74879408-be5a-7023-88c7-3e8543369abf
  2 4addafee-1e25-3808-a5c8-fa4096432681
  3 706dc265-c0d7-8384-9569-6e9e928450f4
  4 76239d99-9a23-01bc-9cda-704429d1c67c
  5 957b37d8-2394-86ef-84cf-ac49dda952ee
  6 a313c5f2-7cc4-18cc-bec6-f52a2c51ecb5
  7 1fae5801-e53e-32f1-9117-9e36e5b56a15
  8 467e8146-0962-5c43-9ffd-951c768f058b
  9 788ee217-c3fa-16fb-9c7a-787bc7c60c5a
 10 d320fdbe-aeb7-3116-bfad-922797e3445d
 11 89894c98-9165-6a37-a095-b30ef440f1c9
 12 63036957-70b2-2e60-b02c-ddb6f1f84a42
 13 1498cc55-f2ad-5912-ab2e-7e7911d87214
 14 722bfca9-1be0-41cd-ae80-85ee6979a5e3
 15 1026f25a-f0d4-02bc-8c1d-758c0dbea573
 16 57a6acb2-05f4-3aa0-ac20-2c5a7e2e110b
 17 12a1063d-e00d-61ed-a086-76737d250ed4

Explanation

Explain the mask digits. The version nibble (13th hex digit) of each GUID, read in order, gives 73808135136254036. Exactly this sequence comes out of new Random(963).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 15 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

Related