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Why do they need to use encryption mechanisms that were invented by an organization which has been known to abuse these mechanisms? "The Americans distributed

Why do they need to use encryption mechanisms that were invented by an organization which has been known to abuse these mechanisms? "The Americans distributed a 22-page explanation of its design and a summary of attempts to break them" That doesn't really sound like a peer review :)

tptacek 9y ago
SIMON and SPECK have received peer review: https://scholar.google.com/scholar?hl=en&q=speck+cipher&btnG=&as_sdt=1%2C14&as_sdtp= https://scholar.google.com/scholar?hl=en&q=speck+cipher&btnG...
- b3lvedere 9y ago
  I stand corrected. Thank you.
- Chaebixi 9y ago
  Peer review isn't a panacea. It's totally possible that the NSA knows of a vulnerability or class of vulnerabilities that the rest of the peer review community doesn't. The cipher could be bad but still pass peer review (or it could be better than publicly known, like DES was). In any case, it seems like the NSA was dragging its feet in trying to fully explain the designs (from the OP): > Finally, at a March 2017 meeting in Hamilton, New Zealand, the Americans distributed a 22-page explanation of its design and a summary of attempts to break them - the sort of paper that formed part of what delegates had been seeking since 2014. Given they're more recent history, I'd be mistrustful. It seems to me that the design of a good cipher should be done totally in the open, so any vulnerabilities are inadvertent. This includes explaining the design and the decisions and trade-offs that brought you there.
  - tptacek 9y ago
    What aspects of the design do you feel needed explanation? In what sense are these not mainstream cipher designs?
    - Chaebixi 9y ago
      I'm not a cryptographer, so I only know what's in the OP. However, it's clear important design information the ISO cryptographers wanted was being withheld by the NSA for at least 3 years.
  - ethbro 9y ago
    > It seems to me that the design of a good cipher should be done totally in the open, so any vulnerabilities are inadvertent. This includes explaining the design and the decisions and trade-offs that brought you there. Implausible, considering that the mathematical attacks NSA is aware of but designing ciphers to be resistant to are still classified and currently being used by the NSA against older generation ciphers. See history of differential cryptanalysis and DES design. https://en.m.wikipedia.org/wiki/Differential_cryptanalysis https://en.m.wikipedia.org/wiki/Differential_cryptanalysis
    - throwaway2048 9y ago
      This is speculation, based upon a time when the academic cryptoanalysis community was pretty much nonexistent. I find it exceedingly unlikely that the NSA is years ahead of public efforts on this front in 2017.
      - compiler-guy 9y ago
        I find it plausible due to the asymmetry of information flow. Everything known by the public is also known by the NSA, but the NSA only tells the public what it wants them to know. That practically guarantees that there is a lot they know that we don't. Of course that proves nothing about this specific instance, and measuring "how far ahead" in years is hard, but I think it is likely the NSA has some extremely sophisticated techniques that we know nothing about.
        ethbro 9y ago
        The devil's advocate to that is offered by tptacek in other thread: that NSA's efforts are simultaneously hurt by the fact they don't openly engage with the academic cryptography community. Whereas the public community is made stronger by its interactions.
kurthr 9y ago
Instead, you can have one designed by a different group of cryprographers... Would you prefer Russian, Chinese, or Israeli? Is a covert shill workimg for one of them preferable? They are all going to be peer reviewed before becoming a standard like AES was reviewed, and they are much less complex. I view political subversion of the technical process as a bigger issue. Paranoia is fine, but you have to pick your battles.
- b3lvedere 9y ago
  Of course. Everything can both be used and abused. And maybe the inventor can abuse it the most of all. It seems though, regarding the complex dependency on encrypted information, abuse can have epic results in a very short time. Everybody can purchase a huge analysis network in minutes and have the information crunched in almost any way possible. Maybe paranoia, but quite possible as well.

tptacek 9y ago

SIMON and SPECK have received peer review: https://scholar.google.com/scholar?hl=en&q=speck+cipher&btnG=&as_sdt=1%2C14&as_sdtp= https://scholar.google.com/scholar?hl=en&q=speck+cipher&btnG...

b3lvedere 9y ago
I stand corrected. Thank you.
Chaebixi 9y ago
Peer review isn't a panacea. It's totally possible that the NSA knows of a vulnerability or class of vulnerabilities that the rest of the peer review community doesn't. The cipher could be bad but still pass peer review (or it could be better than publicly known, like DES was). In any case, it seems like the NSA was dragging its feet in trying to fully explain the designs (from the OP): > Finally, at a March 2017 meeting in Hamilton, New Zealand, the Americans distributed a 22-page explanation of its design and a summary of attempts to break them - the sort of paper that formed part of what delegates had been seeking since 2014. Given they're more recent history, I'd be mistrustful. It seems to me that the design of a good cipher should be done totally in the open, so any vulnerabilities are inadvertent. This includes explaining the design and the decisions and trade-offs that brought you there.
- tptacek 9y ago
  What aspects of the design do you feel needed explanation? In what sense are these not mainstream cipher designs?
  - Chaebixi 9y ago
    I'm not a cryptographer, so I only know what's in the OP. However, it's clear important design information the ISO cryptographers wanted was being withheld by the NSA for at least 3 years.
- ethbro 9y ago
  > It seems to me that the design of a good cipher should be done totally in the open, so any vulnerabilities are inadvertent. This includes explaining the design and the decisions and trade-offs that brought you there. Implausible, considering that the mathematical attacks NSA is aware of but designing ciphers to be resistant to are still classified and currently being used by the NSA against older generation ciphers. See history of differential cryptanalysis and DES design. https://en.m.wikipedia.org/wiki/Differential_cryptanalysis https://en.m.wikipedia.org/wiki/Differential_cryptanalysis
  - throwaway2048 9y ago
    This is speculation, based upon a time when the academic cryptoanalysis community was pretty much nonexistent. I find it exceedingly unlikely that the NSA is years ahead of public efforts on this front in 2017.
    - compiler-guy 9y ago
      I find it plausible due to the asymmetry of information flow. Everything known by the public is also known by the NSA, but the NSA only tells the public what it wants them to know. That practically guarantees that there is a lot they know that we don't. Of course that proves nothing about this specific instance, and measuring "how far ahead" in years is hard, but I think it is likely the NSA has some extremely sophisticated techniques that we know nothing about.
      - ethbro 9y ago
        The devil's advocate to that is offered by tptacek in other thread: that NSA's efforts are simultaneously hurt by the fact they don't openly engage with the academic cryptography community. Whereas the public community is made stronger by its interactions.

kurthr 9y ago

Instead, you can have one designed by a different group of cryprographers... Would you prefer Russian, Chinese, or Israeli? Is a covert shill workimg for one of them preferable? They are all going to be peer reviewed before becoming a standard like AES was reviewed, and they are much less complex. I view political subversion of the technical process as a bigger issue. Paranoia is fine, but you have to pick your battles.

b3lvedere 9y ago
Of course. Everything can both be used and abused. And maybe the inventor can abuse it the most of all. It seems though, regarding the complex dependency on encrypted information, abuse can have epic results in a very short time. Everybody can purchase a huge analysis network in minutes and have the information crunched in almost any way possible. Maybe paranoia, but quite possible as well.