Top all-time · #3170
tobtu.com
Personal blog · tobtu.com/blogsecurityprogramming
tobtu.com is a personal blog at tobtu.com about security and programming. Since 2013, 24 different Hacker News readers have linked it 29 times, most often “DecryptoCat”. No feed was found, so read it on the site itself.
Too few sampled comments (21) to say how often HN recommends it.?
Why HN links it
HN readers link tobtu.com mainly for its critiques of Cryptocat's security bugs, especially the Decryptocat page, and also for write-ups on LastPass, SRP and PRNG flaws. Commenters cite these pages as the reference for Cryptocat's problems.
Summarised by Claude from a sample of 21 HN comments that link here. Each comment is marked recommending, critical or neutral (citing without judging); how this works.
Most-linked posts?
- DecryptoCat10 people · 11 mentions · first linked 2013-07-04
- /decryptocat.php6 people · 6 mentions · first linked 2016-02-19
- Why No One Should Use LastPass3 people · 4 mentions · first linked 2013-09-07
- SRP Is Now Deprecated3 people · 3 mentions · first linked 2021-10-08
What Hacker News says?
LOL. http://tobtu.com/decryptocat.php On a serious matter, javascript (eg all browsers) absolutely needs to change to make the web more trustworthy. I agree with some of the Matasano points[0], but these are the minimum, exhaustively complete changes that would improve browser security: i. js that can be cryptographically signed and verified, a trust model and a browser security policy to enforce it. Think ascii arm…
Comment linking /decryptocat.php
on “Keybase.io”Submitted DecryptoCat as a story · 516 points
HN discussionThe authors have been incompetent. Cryptocat has had several severe bugs that demonstrate cluelessness around fairly simple cryptographic stuff. Here's one walkthrough of their broken PRNG: https://nakedsecurity.sophos.com/2013/07/09/anatomy-of-a-pse... Decryptocat lists some of the other bugs: https://tobtu.com/decryptocat.php The response - "bugs happen, we'll fix them" is okay for most other software, but probabl…
Comment linking /decryptocat.php
on “Open Whisper Systems Partners with Google on End-To-end Encryption for Allo”Submitted SRP Is Now Deprecated as a story · 17 points
HN discussionI am the original author of the software you refer to. Before its complete rewrite (released two months ago), Cryptocat was based on a codebase that I wrote starting in my early undergrad and that was notorious for containing many high-severity vulnerabilities. The most important was "Decryptocat", documented by Steve Thomas [0] but we also had: * AES-CTR counter-reuse (2012) * Biased Fortuna CSPRNG implementation […
Comment linking /decryptocat.php
on “Open Whisper Systems Partners with Google on End-To-end Encryption for Allo”Submitted MegaCracker as a story · 5 points
HN discussionOne of the problems I face when somebody comes along and tells me that they're now on Telegram, Cryptocat, Wire, or whathaveyou is that I might recall an issue but there doesn't seem to be a good up-to-date overview that answers the questions (1) should I trust these people (how bad was it; was it in their code or a dependency?) and (2) is it known to be far less secure than it advertises? (still?) I recall e.g. tha…
Comment linking /decryptocat.php
on “Why I won't recommend Signal anymore”Submitted Why No One Should Use LastPass as a story · 3 points
HN discussionFirst, this is a great article showing the bias in Cryptocat's very awkward PRNG code. However, the off-by-one bias was actually the least of the problems with Cryptocat's random numbers... From reading Steve's write-up, the problem was that their keys were ridiculous undersized, because they called their own function wrong: May 7, 2012 (switched from DH to ECC): myPrivateKey = Cryptocat.randomString(32, 0, 0, 1); A…
Comment linking /decryptocat.php
on “Anatomy of a pseudorandom number generator – visualising Cryptocat's buggy PRNG”Submitted Breaking a PRNG: Is It Called Xor Shift or Xor Shit? as a story · 2 points
HN discussionLastPass has a bit to go until I'd call them a sham. I was talking in general. There have been much worse examples before. Yes there are vulnerabilities in every software. Even if your code is perfect the compiler will generate bugged code. Even if you fix that, the CPU still has bugs. These are certainly hard problems. However there's a difference between a subtle bug caused by a typo and complete lack of understan…
Comment linking /decryptocat.php
on “LastPass RCE vulnerability fixed”Submitted How to mess up with crypto software badly? Some thougths on CryptoCat. as a story · 2 points
HN discussionIn my experience, most malware creators are pretty terrible. Even in 2015 it's common for malware to communicate with C&C servers that have classic SQL injection vulnerabilities. More specifically on the topic of ransomware, have a look at this gem [1], which uses RSA, but the key is 128 ASCII digits. Very similar to the cryptocat disaster. [2] [1] http://blog.cassidiancybersecurity.com/post/2014/02/Bitcrypt... [2]…
Comment linking /decryptocat.php
on “Ransomware Decryptor”Submitted Minimum Password Settings (2022) as a story · 1 points
HN discussionReading about the history of CryptoCat doesn't convince me that it was written by people who knew what they were doing. Look at the RSA key size chronology: 768, 512, 600, 1280, 1024, 1048, ... http://tobtu.com/decryptocat.php
Comment linking /decryptocat.php
on “Secure Messaging Scorecard”Submitted SRP Is Now Deprecated as a story · 1 points
HN discussionGo read http://tobtu.com/decryptocat.php and earlier sources before deciding he's being extremist.
Comment linking /decryptocat.php
on “CryptoCat iOS Application Penetration Test [pdf]”This is probably a good reason ppl stopped using it http://www.tobtu.com/lastpass.php Plus I wouldn't trust any browser plugin with passwords
Comment linking /lastpass.php
on “KeePass: OpenSource Password Manager”This is a good post pointing out some of the problems with CryptoCat http://tobtu.com/decryptocat.php
Comment linking /decryptocat.php
on “Once-starving GnuPG crypto project gets a windfall. Now comes the hard part”> At least if you somewhat trust the reviewer we now know that it has no glaring problems and seems to be well designed. I believe OP was making fun of the review. Cryptocat was full of questionable choices ( https://tobtu.com/decryptocat.php ) as well as widely disputed security claims.
Comment linking /decryptocat.php
on “RusTLS Formal Audit [pdf]”http://www.tobtu.com/lastpass.php why nobody should use lastpass
Comment linking /lastpass.php
on “1Password and the Crypto Wars”This is one of the bugs found in CryptoCat. http://tobtu.com/decryptocat.php
Comment linking /decryptocat.php
on “Encryptr – Free, open-source password manager and e-wallet”This is a comment that appears to endorse mpOTR's broken transcript consistency feature. Also: formal security proofs? Really? Some context: http://tobtu.com/decryptocat.php (Yes, we know you addressed these issues; the page I just linked to says that).
Comment linking /decryptocat.php
on “TextSecure's Private Group Messaging”https://tobtu.com/decryptocat.php
Comment linking /decryptocat.php
on “Dear Cryptocat Users”Relatedly, a recent post on SRP (the most commonly used PAKE) and how it's worse in all cases than PAKEs derived from SPEKE: https://tobtu.com/blog/2021/10/srp-is-now-deprecated/
Comment linking /blog/2021/10/srp-is-now-deprecated/
on “Let’s Talk about PAKE (2018)”http://tobtu.com/decryptocat.php https://blog.crypto.cat/2013/07/new-critical-vulnerability-i... https://news.ycombinator.com/item?id=5989707
Comment linking /decryptocat.php
on “Saltstack: Changing RSA public exponent from 1 to 65537”That's a pretty amazing hyperbole from kaepora (twitter description of incident vs actual e-mail response from Apple). And later, Apple accepted the fix: https://github.com/cryptocat/cryptocat/issues/542#issuecomme... Kaepora is so full of himself, I'm not sure how anyone takes what he says or the apps he writes seriously. Glad that people are putting stock in more consistent developers these days ( http://tobtu.com…
Comment linking /decryptocat.php
on “Cryptocat rejected by Apple”His slides to his talk have been posted. I'll like the video to the talk when it's up. https://tobtu.com/blackhat2022/
Comment linking /blackhat2022/
on “Bscrypt – A cache hard password hash/KDF”No love for KeePass in that article? I recall all those password managers being broken by tobtu.com or various users on Hashcat forums. http://www.tobtu.com/lastpass.php
Comment linking /lastpass.php
on “Security vulnerabilities found on password managers”
