{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

applied cryptography - protocols, algorithms, and source code in c

One of the cryptographers might be paying for the

Info icon This preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Bob knows b, and together they will determine whether a = b, such that Bob does not learn anything additional about a and Alice does not learn anything additional about b. Details are in Section 23.14. Protocol #4 This is another problem for secure multiparty computation [1373]: A council of seven meets regularly to cast secret ballots on certain issues. (All right, they rule the world—don’t tell anyone I told you.) All council members can vote yes or no. In addition, two parties have the option of casting “super votes”: S-yes and S-no. They do not have to cast super votes; they can cast regular votes if they prefer. If no one casts any super votes, then the majority of votes decides the issue. In the case of a single or two equivalent super votes, all regular votes are ignored. In the case of two contradicting super votes, the majority of regular votes decides. We want a protocol that securely performs this style of voting. Two examples should illustrate the voting process. Assume there are five regular voters, N1 through N5, and two super voters: S1 and S2. Here’s the vote on issue #1: S1 S-yes S2 no N1 no N2 no N3 no N4 yes N5 yes In this instance the only vote that matters is S1 ’s, and the result is “yes.” Here is the vote on issue #2: S1 S-yes S2 S-no N1 no N2 no N3 no N4 N5 yes yes Here the two super votes cancel and the majority of regular “no” votes decide the issue. If it isn’t important to hide the knowledge of whether the super vote or the regular vote was the deciding vote, this is an easy application of a secure voting protocol. Hiding that knowledge requires a more complicated secure multiparty computation protocol. This kind of voting could occur in real life. It could be part of a corporation’s organizational structure, where certain people have more power than others, or it could be part of the United Nations’s procedures, where certain nations have more power than others. Multiparty Unconditionally Secure Protocols This is just a simple case of a general theorem: Any function of n input...
View Full Document

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern