4 ms·

Anybody have any idea on when we'll be able to use elliptic curve encryption with GPG? According to tptacek, that's in the works, but seems like that didn't ma

Anybody have any idea on when we'll be able to use elliptic curve encryption with GPG? According to tptacek, that's in the works, but seems like that didn't make it into this release.

antocv 13y ago
I wonder when we will be able to use some GOST ciphers with it, just for fun and diversification from NIST ciphers. Does anyone know what the Chinese equivalent of NIST is? What does China use?
- JoachimS 13y ago
  In terms om symmetric ciphers we know of two chinese ones: sms4 and zuc. The latter has also been accepted as standard by 3GPP (SAGE). https://en.wikipedia.org/wiki/SMS4 https://en.wikipedia.org/wiki/SMS4 https://en.wikipedia.org/wiki/Zuc_stream_cipher https://en.wikipedia.org/wiki/Zuc_stream_cipher Not sure why anybody would want to use them or the GOST standards unless required/forced to do so.
  - Smegger 13y ago
    Well if you were to use a mix of encryption algorithms from the US and China while each may have a back door in their own they are most assuredly not going to share them with each other. So it you encrypted a message with say RSA and $random_chinesse_cipher neither government would be likely to have the ability to read it.
  - Steuard 13y ago
    I think the idea is to encrypt with multiple cyphers, each endorsed by a different government (preferably mutually mistrustful governments). That way, in principle, the Chinese may have a backdoor to one layer and the US to another, but they'd need to work together to break your whole message. I have no idea how useful this would be in practice.
    - betterunix 13y ago
      I suspect that the NSA would be aware of weaknesses in Chinese ciphers as much as in American ciphers, so I doubt that this would help much...
      - tedks 13y ago
        It avoids backdoors. Assume that the Chinese government has backdoored its ciphers, and the American government has backdoored its ciphers, and the two governments don't want to cooperate. If you cascade the two ciphers, the American government needs to find a real weakness in the Chinese cipher, and the Chinese government needs to find a real weakness in the American cipher. Which they might have, but they at least can't use backdoors at this point.
        chimeracoder 13y ago
        > If you cascade the two ciphers, That assumes that f(g(x)) is harder to invert than either f(x) or g(x) individually, which is not true in the general case for encryption schemes. It is quite possible that (f∘g) can be cracked in a way that neither f or g can individually.
        tedks 13y ago
        I've heard this before, and have no background in crypto so I can't dispute it, but I'm unsure as to how this makes sense. Certainly if I encrypt something with AES, and then encrypt it with Twofish, using different keys each time, how is this different from encrypting any other arbitrary data with either of those ciphers?
        betterunix 13y ago
        It is worth pointing out that composing two block ciphers like this only adds one bit of security, due to the meet-in-the-middle attack (assuming that the composition is otherwise secure, etc.).

Anybody have any idea on when we'll be able to use elliptic curve encryption with GPG? According to tptacek, that's in the works, but seems like that didn't make it into this release.

antocv 13y ago

I wonder when we will be able to use some GOST ciphers with it, just for fun and diversification from NIST ciphers. Does anyone know what the Chinese equivalent of NIST is? What does China use?

JoachimS 13y ago
In terms om symmetric ciphers we know of two chinese ones: sms4 and zuc. The latter has also been accepted as standard by 3GPP (SAGE). https://en.wikipedia.org/wiki/SMS4 https://en.wikipedia.org/wiki/SMS4 https://en.wikipedia.org/wiki/Zuc_stream_cipher https://en.wikipedia.org/wiki/Zuc_stream_cipher Not sure why anybody would want to use them or the GOST standards unless required/forced to do so.
- Smegger 13y ago
  Well if you were to use a mix of encryption algorithms from the US and China while each may have a back door in their own they are most assuredly not going to share them with each other. So it you encrypted a message with say RSA and $random_chinesse_cipher neither government would be likely to have the ability to read it.
- Steuard 13y ago
  I think the idea is to encrypt with multiple cyphers, each endorsed by a different government (preferably mutually mistrustful governments). That way, in principle, the Chinese may have a backdoor to one layer and the US to another, but they'd need to work together to break your whole message. I have no idea how useful this would be in practice.
  - betterunix 13y ago
    I suspect that the NSA would be aware of weaknesses in Chinese ciphers as much as in American ciphers, so I doubt that this would help much...
    - tedks 13y ago
      It avoids backdoors. Assume that the Chinese government has backdoored its ciphers, and the American government has backdoored its ciphers, and the two governments don't want to cooperate. If you cascade the two ciphers, the American government needs to find a real weakness in the Chinese cipher, and the Chinese government needs to find a real weakness in the American cipher. Which they might have, but they at least can't use backdoors at this point.
      - chimeracoder 13y ago
        > If you cascade the two ciphers, That assumes that f(g(x)) is harder to invert than either f(x) or g(x) individually, which is not true in the general case for encryption schemes. It is quite possible that (f∘g) can be cracked in a way that neither f or g can individually.
        tedks 13y ago
        I've heard this before, and have no background in crypto so I can't dispute it, but I'm unsure as to how this makes sense. Certainly if I encrypt something with AES, and then encrypt it with Twofish, using different keys each time, how is this different from encrypting any other arbitrary data with either of those ciphers?
        betterunix 13y ago
        It is worth pointing out that composing two block ciphers like this only adds one bit of security, due to the meet-in-the-middle attack (assuming that the composition is otherwise secure, etc.).