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Has anyone done the same level of analysis on TextSecure ? I feel like their model/seriousness is better but there might be flaws in the implementation (or prot

Has anyone done the same level of analysis on TextSecure ? I feel like their model/seriousness is better but there might be flaws in the implementation (or protocol) and being audited might highlight some of them.

natdempk 13y ago
I don't believe they've had an independent security audit. I think their team however is comprised of more respected cryptographers like Moxie Marlinspike, who introduced the concept of SSL stripping, one of the issues that was found in the CryptoCat app. I mean no disrespect to CryptoCat, and more eyes can always find something someone overlooked, but I think the Open Whisper Systems (TextSecure) team is stronger and using better cryptographic techniques.
- tptacek 13y ago
  TextSecure also has design contributions from Trevor Perrin, who is also amazing.
  - nathan-at-least 13y ago
    natdempk and tptacek have both asserted that TextSecure is trustworthy and solid by dint of being implemented and designed by reliable experts. This pretty much boils down to argument by authority. mandalar12 asks about "the same level of analysis on TextSecure". Since our (Least Authority's) audit and the iSEC audit are public, random people on the internet can know what that level is, without having to know or rely on Least Authority or iSEC to be non-malicious. With enough eyes all bugs are shallow, but to whom? We need to communicate transparently to achieve this ideal. Disclaimers: I worked on the Least Authority audit of Cryptocat; I've worked at iSEC in the past; I've met Moxie Marlinspike and Trevor Perrin and greatly respect their expertise and motivations; I also don't know if they've been infected by malicious puppetmaster aliens since I last saw them.
    - daira 13y ago
      I don't actually see any assertions on this thread by natdempk or tptacek claiming that TextSecure is "trustworthy" and/or "solid". Did I miss something? My own opinion is that both strong cryptographic and security engineering expertise on the part of designers and implementors, and multiple independent published security audits, are necessary to consider an app trustworthy -- but still not sufficient, given the poor state of platform security and the lack of support most current platforms (operating systems, browsers, etc.) give for isolation between apps. Disclaimer: I worked on the Least Authority audit of Cryptocat, and in general get paid for similar auditing. I'm also designing a programming language (Noether) that is intended to facilitate security reviews.
- illumen 13y ago
  No need for an of audit TextSecure... just go to their github issues page. Plenty of open bugs and regressions, some of them as serious as some of the ones in the latest CryptoCat app audits. For example, one issue where some messages sent are not being encrypted. Even with 'amazing' contributors, bugs are still there in TextSecure.
  - tptacek 13y ago
    I just reviewed all open and closed bugs in TextSecure's Issues page and didn't see a single crypto protocol bug. Admittedly, I looked quickly and casually. Could you point us to one?
    - illumen 13y ago
      "I just reviewed all open and closed bugs in TextSecure's Issues page and didn't see a single crypto protocol bug. Admittedly, I looked quickly and casually. Could you point us to one?" You could not have reviewed all open and closed bugs in 8 minutes ;) Issue 1073: https://github.com/WhisperSystems/TextSecure/issues/1073 https://github.com/WhisperSystems/TextSecure/issues/1073 Another one: Just sent an encrypted photo to someone? The photo is stored unencrypted on your phone. Edit: group messages were also sent unencrypted, but this was fixed. https://github.com/WhisperSystems/TextSecure/issues/32 https://github.com/WhisperSystems/TextSecure/issues/32 Edit2: ok, I see your point. Maybe they do crypto well as you say, but they don't seem to do software engineering well, or UI design for secure text messaging well. Sending messages unencrypted, and leaving messages unencrypted on the phone is a big fail in overall security of the app. It's meant to encrypt things, and it doesn't. That it doesn't put in tests for these things, and that it did not publish the independent security audit should cause everyone to reconsider using the TextSecure app for its stated purpose.
      - tptacek 13y ago
        I read that issue especially carefully since it was on the front page, and it doesn't look like a crypto protocol bug. I'm actually not sure what that bug is. A crypto protocol bug is something like "TextSecure tried to implement secure file transfer, used the CTR block cipher mode, and managed to make the keystreams collide, so that passive attackers could recover file contents from encrypted streams". The general point you made, that all applications have bugs (and thus security bugs) is valid. I'm drawing a line that you're not drawing, between design flaws in cryptosystems and random iOS/Android mistakes.
- kaeporan 13y ago
  iSEC also audited TextSecure, but TextSecure chose not to publish the audit.
  - tptacek 13y ago
    And? What does this have to do with the parent comment?
    - aeontech 13y ago
      The grandparent asked whether they have had a security audit, and parent said "I don't believe they've had an independent security audit." Seems like a straightforward reply to those.
      - tptacek 13y ago
        Oh. Duh. You're right. I was skimming my threads and lost the context. Thanks for pointing this out.
  - epsylon 13y ago
    They didn't choose not to publish. https://news.ycombinator.com/item?id=7520581 https://news.ycombinator.com/item?id=7520581

natdempk 13y ago

I don't believe they've had an independent security audit. I think their team however is comprised of more respected cryptographers like Moxie Marlinspike, who introduced the concept of SSL stripping, one of the issues that was found in the CryptoCat app. I mean no disrespect to CryptoCat, and more eyes can always find something someone overlooked, but I think the Open Whisper Systems (TextSecure) team is stronger and using better cryptographic techniques.

tptacek 13y ago
TextSecure also has design contributions from Trevor Perrin, who is also amazing.
- nathan-at-least 13y ago
  natdempk and tptacek have both asserted that TextSecure is trustworthy and solid by dint of being implemented and designed by reliable experts. This pretty much boils down to argument by authority. mandalar12 asks about "the same level of analysis on TextSecure". Since our (Least Authority's) audit and the iSEC audit are public, random people on the internet can know what that level is, without having to know or rely on Least Authority or iSEC to be non-malicious. With enough eyes all bugs are shallow, but to whom? We need to communicate transparently to achieve this ideal. Disclaimers: I worked on the Least Authority audit of Cryptocat; I've worked at iSEC in the past; I've met Moxie Marlinspike and Trevor Perrin and greatly respect their expertise and motivations; I also don't know if they've been infected by malicious puppetmaster aliens since I last saw them.
  - daira 13y ago
    I don't actually see any assertions on this thread by natdempk or tptacek claiming that TextSecure is "trustworthy" and/or "solid". Did I miss something? My own opinion is that both strong cryptographic and security engineering expertise on the part of designers and implementors, and multiple independent published security audits, are necessary to consider an app trustworthy -- but still not sufficient, given the poor state of platform security and the lack of support most current platforms (operating systems, browsers, etc.) give for isolation between apps. Disclaimer: I worked on the Least Authority audit of Cryptocat, and in general get paid for similar auditing. I'm also designing a programming language (Noether) that is intended to facilitate security reviews.
illumen 13y ago
No need for an of audit TextSecure... just go to their github issues page. Plenty of open bugs and regressions, some of them as serious as some of the ones in the latest CryptoCat app audits. For example, one issue where some messages sent are not being encrypted. Even with 'amazing' contributors, bugs are still there in TextSecure.
- tptacek 13y ago
  I just reviewed all open and closed bugs in TextSecure's Issues page and didn't see a single crypto protocol bug. Admittedly, I looked quickly and casually. Could you point us to one?
  - illumen 13y ago
    "I just reviewed all open and closed bugs in TextSecure's Issues page and didn't see a single crypto protocol bug. Admittedly, I looked quickly and casually. Could you point us to one?" You could not have reviewed all open and closed bugs in 8 minutes ;) Issue 1073: https://github.com/WhisperSystems/TextSecure/issues/1073 https://github.com/WhisperSystems/TextSecure/issues/1073 Another one: Just sent an encrypted photo to someone? The photo is stored unencrypted on your phone. Edit: group messages were also sent unencrypted, but this was fixed. https://github.com/WhisperSystems/TextSecure/issues/32 https://github.com/WhisperSystems/TextSecure/issues/32 Edit2: ok, I see your point. Maybe they do crypto well as you say, but they don't seem to do software engineering well, or UI design for secure text messaging well. Sending messages unencrypted, and leaving messages unencrypted on the phone is a big fail in overall security of the app. It's meant to encrypt things, and it doesn't. That it doesn't put in tests for these things, and that it did not publish the independent security audit should cause everyone to reconsider using the TextSecure app for its stated purpose.
    - tptacek 13y ago
      I read that issue especially carefully since it was on the front page, and it doesn't look like a crypto protocol bug. I'm actually not sure what that bug is. A crypto protocol bug is something like "TextSecure tried to implement secure file transfer, used the CTR block cipher mode, and managed to make the keystreams collide, so that passive attackers could recover file contents from encrypted streams". The general point you made, that all applications have bugs (and thus security bugs) is valid. I'm drawing a line that you're not drawing, between design flaws in cryptosystems and random iOS/Android mistakes.
kaeporan 13y ago
iSEC also audited TextSecure, but TextSecure chose not to publish the audit.
- tptacek 13y ago
  And? What does this have to do with the parent comment?
  - aeontech 13y ago
    The grandparent asked whether they have had a security audit, and parent said "I don't believe they've had an independent security audit." Seems like a straightforward reply to those.
    - tptacek 13y ago
      Oh. Duh. You're right. I was skimming my threads and lost the context. Thanks for pointing this out.
- epsylon 13y ago
  They didn't choose not to publish. https://news.ycombinator.com/item?id=7520581 https://news.ycombinator.com/item?id=7520581