Bentham's Gaze
benthamsgaze.org · Group blog · on HN since 2015
Bentham's Gaze is the blog of University College London's information security research group, covering security failures, cryptography, and the law.
What HN saysHN links it for analysis of the Post Office Horizon scandal and the English legal presumption that computers work correctly, plus UK cybersecurity policy.
40HN people shared it
18linked it in comments
75stories submitted
796story points
5 months agolast shared
2015people per year2026
Most-shared posts
- 1Insecure by design: protocols for encrypted phone calls7 people · 176 points · first shared 2016 · 30 comments on HN
- 2What went wrong with Horizon: learning from the Post Office Trial7 people · 40 points · first shared 2021 · 19 comments on HN
- 3The English and Welsh legal rule: computers are presumed to operate correctly6 people · 8 points · first shared 2022 · 2 comments on HN
- 4How contactless cards are still vulnerable to relay attack2 people · 60 points · first shared 2016 · 48 comments on HN
- 5Vulnerability in the enforcement of group permissions in Linux containers2 people · 7 points · first shared 2022 · 1 comments on HN
- 6“The pool’s run dry” – analyzing anonymity in Zcash2 people · 7 points · first shared 2018 · discussion on HN
- 7Criminals exploit vuln in Chip and PIN that banks claimed would never be seen2 people · 5 points · first shared 2015 · 5 comments on HN
- 8Tampering with OpenPGP signed messages by exploiting multi-part messages2 people · 2 points · first shared 2018 · discussion on HN
- 9The Quiet Numbers Station: Decoding Nineteen Years of GPS Cryptography2 people · 2 points · first shared 2026 · discussion on HN
- 10The politics of the NHS WannaCrypt ransomware outbreak2 people · 1 points · first shared 2017 · discussion on HN
- 11International Comparison of Bank Fraud Reimbursement: Perceptions and Contracts2 people · 1 points · first shared 2016 · discussion on HN
- 12The legal rule that computers are presumed to be operating correctly (2022) [pdf]1 people · 145 points · first shared 2022 · 104 comments on HN
- 13Scaling Tor Hidden Services1 people · 85 points · first shared 2015 · 2 comments on HN
- 14On the hunt for Facebook’s army of fake likes1 people · 69 points · first shared 2016 · 59 comments on HN
- 15How 4chan and The_Donald Influence the Fake News Ecosystem1 people · 54 points · first shared 2017 · 25 comments on HN
What HN people wrote when they linked it
sjmurdoch · 2016-07-14
My comments on some of the key findings of the report are here: https://www.benthamsgaze.org/2016/07/13/cybersecurity-supporting-a-res…
thinkingemote · 2024-12-02
For some background. The legal presumption dates from 1997.
"Previously, section 69 of the Police and Criminal Evidence Act 1984 required anyone introducing computer-generated evidence to show the system was operating correctly and not being used improperly.
The change followed the Law Commission’s 1997 review of the law on hearsay evidence."[1]
from https://www.lawgazette.co.uk/law/it-experts-call-for-review-of-compute…
[1] review https://cloud-platform-e218f50a4812967ba1215eaecede923f.s3.amazonaws.c… (page 197)
---
Another interesting briefing note:
"The legal rule that computers are presumed to be operating correctly – unforeseen and unjust consequences": https://www.benthamsgaze.org/2022/06/30/the-legal-rule-that-computers-…
They suggest, when requested, that a party gets:
- records of known errors and bugs in the system, their effect, and the actions taken in response
- description of information security and other relevant standards and processes followed
- reports of audits performed on the system and how it is managed,
- evidence showing that reports of errors are managed properly and that changes to the system are properly controlled
- evidence confirming that the search for documents was performed adequately, and was done so by a person with…
NelsonMinar · 2026-06-05
Summary from the study author: https://www.benthamsgaze.org/2026/06/02/the-quiet-numbers-station-deco…
PDF of article (page 62) https://cdn.coverstand.com/61061/865273/2c88ea662e2b574787232d6b66f1ae…
rwmj · 2025-07-11
I did read a very technical report about this which obviously now I can't find :-( My takeaways were: (1) They didn't bother with double-entry bookkeeping. (2) It was a distributed system which no one fully understood and was not based on any normal distributed system principles. (3) Developers made ad hoc changes to the code and even database to temporarily patch things up, even going so far as to hard-code database ids into special cases throughout the code.
Edit: I think this one: https://www.judiciary.uk/wp-content/uploads/2019/12/bates-v-post-offic… Also related article: https://www.benthamsgaze.org/2021/07/15/what-went-wrong-with-horizon-l…
ndsipa_pomu · 2024-07-17
Unfortunately, in England and Wales, courts consider computers, as a matter of law, to have been working correctly unless there is evidence to the contrary. Therefore, evidence produced by computers is treated as reliable unless other evidence suggests otherwise. This way of handling evidence is known as a ‘rebuttable presumption’. A court will treat a computer as if it is working perfectly unless someone can show why that is not the case.
(taken from https://www.benthamsgaze.org/2022/06/30/the-legal-rule-that-computers-…
The sub post masters did not have access to the evidence required to show that the Horizon system was buggy and so were denied justice.
mavhc · 2024-01-16
They were using Riposte from https://www.eschergroup.com/riposte-platform/ and Oracle.
They were using dial up ISDN lines to send the data back, but Riposte didn't support that, or scale to 20k terminals, so that was all new code
In general they had a distributed database that couldn't do ACID
https://www.postofficetrial.com/2019/12/fisking-horizon-trial-1-meanin… https://www.computerweekly.com/news/252496560/Fujitsu-bosses-knew-abou… https://www.benthamsgaze.org/2021/07/15/what-went-wrong-with-horizon-l…
tauchunfall · 2024-01-13
There is also a detailed description of the system in [1].
An interesting incidence/problem report is in [2] at 1h:03m:00s, where an replication error in their Riposte message store system is described. After a defect counter hardware was replaced, it will fill its empty store with messages from other counters.
[1] "Technical Appendix to Judgment (No.6) “Horizon Issues”", https://www.judiciary.uk/wp-content/uploads/2022/07/bates-v-post-offic…
[2] "Alvin Finch - Richard Coleman - Day 54 AM (17 May 2023) - Post Office Horizon IT Inquiry", https://www.youtube.com/watch?v=H0_-ebCVU5k&t=3780
[3] Steven Murdoch: "What went wrong with Horizon: learning from the Post Office Trial", https://www.benthamsgaze.org/2021/07/15/what-went-wrong-with-horizon-l…
amiga386 · 2024-01-11
More history and legal opinion on this: https://www.benthamsgaze.org/2022/06/30/the-legal-rule-that-computers-…
suzzer99 · 2023-10-01
This is the first I've heard of this scandal. I'm curious what the major problems were with the software that caused the discrepancies. Dropped connections? Wikipedia didn't go into much detail with that.
Ok I found this: https://www.benthamsgaze.org/2021/07/15/what-went-wrong-with-horizon-l…
1vuio0pswjnm7 · 2023-08-25
From the onionbalance site
https://www.benthamsgaze.org/wp-content/uploads/2015/11/sucu-torscalin…
daverol · 2022-02-14
https://www.benthamsgaze.org/2021/07/15/what-went-wrong-with-horizon-l… had some reflections on this after the previous High Court trial
tptacek · 2018-05-15
Speaking of that:
https://www.benthamsgaze.org/2018/05/15/tampering-with-openpgp-digital…
willtim · 2017-05-14
Don't blame the NHS IT staff. The decision to not pay for XP security updates came from the highest level, the UK Tory government: https://www.benthamsgaze.org/2017/05/13/the-politics-of-the-nhs-wannac…
dgacmu · 2016-09-09
They are, when it comes to bank fraud. Particularly the UK. See, for example, a lot of Ross Anderson's work, such as: https://www.benthamsgaze.org/2016/06/02/international-comparison-of-ba…
forgotpwtomain · 2016-02-25
Direct link to the referenced article (probably preferable to an article about an article?): https://www.benthamsgaze.org/2016/01/19/insecure-by-design-protocols-f…
wmt · 2016-01-20
The original story at https://www.benthamsgaze.org/2016/01/19/insecure-by-design-protocols-f… seems to be not coping well with the traffic, here's the Google cache: http://webcache.googleusercontent.com/search?q=cache:rBNjGS8jxX8J:http…
ldarby · 2021-07-18
I don't think you (or the sibling comment) got my point. No where am I "excusing" bugs. Civil engineering bugs are indeed a fact of life too, just check the god damn news.
What I'm saying, is that I think where PHK says "nobody sat down and documented precisely what went wrong", I think he is just wrong.
The guy in the Computerphile video, Steven Murdoch wrote this article:
https://www.benthamsgaze.org/2021/07/15/what-went-wrong-with-horizon-l…
which has further details of the bugs, e.g.
"There is a window of time between a user printing and cutting-off a report. If another user was to perform a transaction during that window, that transaction may not show on the report."
which is from the long and very detailed judgment: https://www.benthamsgaze.org/wp-content/uploads/2021/07/Bates-and-Ors-…
The problem that needs investigating here is the miscarriage of justice, apparently the post office was aware of the bugs at the same time as prosecuting people for falling victim to the bugs, in order to save face about their IT decision.
zahllos · 2017-07-16
Not in academic terms, no. tl;dr IBE refers to a specific process of mathematically using identifying data as a public key like a phone number or email.
As always with cryptography you have a key exchange/identity binding problem: if you receive my public key, how do you know it actually came from me? There are a few solutions to this problem:
1. Certificate authorities do an ID check (domain or extended validation). You know the cert is valid because (in theory) the CA doesn't sign unless it too is convinced and you trust them to do a good job (there's a whole history of CA issues and implementation problems I won't discuss further here - this is by and large the concept).
2. Web-of-Trust/Keybase - the valid key is signed by enough other people you trust / signs enough other public statements from accounts you trust you don't think MITM can happen.
3. Compare hashes (fingerprints) - OTR, OMEMO, Signal, WhatsApp, ZRTP et al. You have the right key because you trust the digest function.
4. Authenticated Key Exchange e.g. PAKE, SPAKE, NAXOS etc.
IBE solves the key exchange problem a different way - what if your public key was some identifiable piece of information (not necessarily biometric as others have suggested, but) e.g. an email address or telephone number? To realise this you need a key management server to go from these public keys to a private key, via a protected master secret and other global parameters, see https://crypto.stanford.edu/~dabo/papers/bfibe.pdf ,…