See roman_attestation.sig and roman_attestation.txt in this directory for
Roman Semenov's (@poma) signed attestation.
Challenge file: https://ppot.blob.core.windows.net/public/challenge_0003
Blake2b hash of challenge_0003: 9ff247f138a1175105137aced8c9766c5eeccef35b892c62c55eae787301991b05b66649b00c48f27501b30d1538f5d80e2da3edf163a9785fba5b47352f7d04
Generated response file: https://ppot.blob.core.windows.net/public/response_0003_poma
Blake2b hash of response_0003_poma: 65c6c7bdf97d1259ccac23b02fc35af47381899193a0b9d382c5bee52159d5d11ceaa64cf85584713e954bdfa5c0e628ab75b48d0fda7dfb6d1690d95361201c
Blake2b hash of the new_challenge file for participant #4: 01401c5e781fc7c8aae99b160f14a86b16a0a5e319d48fd04eaba3db8a0fefa7bf0854bc9bf6789336b8680f261151bc1d2aca163aa74c5019c817bfdbc4d21d
The above new_challenge file: https://ppot.blob.core.windows.net/public/challenge_0004
Hi everyone,
I finished computing a response file for the third round. This is a test contribution from tornado.cash team.
Date: 13-15 September 2019
Name: Roman Semenov
Location: N/A
Device(s): My server in 3rd party datacenter in Moscow (colocation)
Challenge hash:
9ff247f1 38a11751 05137ace d8c9766c
5eeccef3 5b892c62 c55eae78 7301991b
05b66649 b00c48f2 7501b30d 1538f5d8
0e2da3ed f163a978 5fba5b47 352f7d04
Challenge file claims it's based on the response hash:
edec0294 eb450803 ec0ef7e1 7573f238
5663016b 6b47b9cc 8c9396cb 5ed36732
fcc6b6e3 abf5f8ac 61d6761d d565b203
936e475a 00f6e9ba 047e5991 4340fd1f
Response hash:
65c6c7bd f97d1259 ccac23b0 2fc35af4
73818991 93a0b9d3 82c5bee5 2159d5d1
1ceaa64c f8558471 3e954bdf a5c0e628
ab75b48d 0fda7dfb 6d1690d9 5361201c
Software used: https://github.com/kobigurk/phase2-bn254/commit/bf852c168676a7afc5dd17b47ff9b8f394aeab8a
Entropy sources: concatenated bytes from /dev/urandom from 5 different machines (including my laptop, google cloud, aws cloud, own server)
Time taken: ~10 hours
Side channel defenses:
* Left batch job processor (not a webserver, jobs are not interactive) for my other unrelated service running. This has both positive (additional unrelated work is happening on the server) and negative (larger attack surface) sides
Other defenses:
* Have not used swap space
Post processing:
* Uploaded the response file to AWS instance and then Wei Jie transferred it to Azure
* Rebooted the the machine
While there were some security measures, there is no guarantee that the machine was not compromised as it works as a public webserver. I intend to participate again later in a much more secure environment.
Attached the attestation as a file and a GPG signature. The signature can be verified with gpg --verify roman_attestation.sig roman_attestation.txt.