Re: Interesting Discussion with US Government Computer Expert

From: George Ou (533george_ou234_at_netzero234.com)
Date: 08/31/03

  • Next message: dsr_at_Florence.edu: "Re: Interesting Discussion with US Government Computer Expert" 
    Date: Sun, 31 Aug 2003 01:12:34 GMT

    On Sat, 30 Aug 2003 01:06:00 GMT, dsr@Florence.edu wrote:

    >On Fri, 29 Aug 2003 16:41:14 -0400 (EDT), "No One"
    ><no-one-no-spam@home.com> wrote:
    >
    >>OK. Here's the deal. I work for the government as a consultant on SIPRNET.
    >>Had a discussion with a fellow contractor who works for a government agency
    >>in Maryland. (Hint, Hint).
    >>
    >>He implied that RSA-type keys were inherently unsecure because of known
    >>plaintext attacks. That is if I have your public key and use it to encrypt
    >>one or more text messages (or I guess any other data), by knowing the
    >>algorithm I can calculate the private key by comparing the cipherttext and
    >>the know plaintext.
    >>
    >>I think there has to be more to the story. Unfortunately, my knowledge of
    >>this encryption stops at knowing what group (i.e. this one) to ask the
    >>question in.
    >>
    >>There has to be more to the story, right guys?? Probably involving
    >>factoring very large prime numbers?
    >>
    >>I don't really need to know the answer to this question, but it will
    >>provide an indication of how seriously I should take anything else this guy
    >>says.
    >>
    >>Thanks
    >
    >Not everybody uses public key systems to encrypt plaintext. Some
    >people use an RSA or Diffie Hellman scheme to exchange a random
    >symmetric key. The random symmetric key is then used as a start key
    >for a more robust symmetric key system. Although some of the more
    >robust systems are not commercially available without screening I
    >don't think they are completely unavailable.

    No, PKC is almost never used to encrypt data. PGP mail, S/MIME, SSL,
    EFS, and any other app I can think of all use PKC to protect the
    symmetric session keys to kick start the symmetric crypto session.

    George Ou
    http://www.LANArchitect.net

  • Next message: dsr_at_Florence.edu: "Re: Interesting Discussion with US Government Computer Expert"

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