{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

ashoff2-BitCommitment

ashoff2-BitCommitment - Bit Commitment Fair Coin Flips and...

This preview shows pages 1–7. Sign up to view the full content.

Bit Commitment, Fair Coin Flips, and One-Way Accumulators Matt Ashoff 11/9/2004 Cryptographic Protocols

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Outline Bit Commitment Definition Properties Applications Implementations Fair Coin Flips Definition Implementations One-Way Accumulators Definition Example Motivation Applications References
Definition Bit Commitment Goal is to ensure bit commitment. Simplest example: Decide who goes first in a game If Bob guesses correctly, he goes Alice picks a bit (0 or 1) and locks it in a box Bob guesses a bit The box is opened to see if he is right Two parts: Commitment Unveiling Must ensure that: Alice cannot change her bit after Bob guesses Bob cannot know what Alice’s bit is until she unveils it Assume no trusted third-party

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Properties Bit Commitment Ideally, bit commitment has two interesting properties: It is unconditionally secure if implemented correctly As opposed to computationally secure, which is a requirement for most algorithms It requires only a noisy channel However, implementing the algorithm ideally is the key
Applications Bit Commitment Zero-Knowledge Protocols Identification Schemes Multi-party Computation Fair Coin Flips Electronic Voting

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Implementations Bit Commitment Symmetric Cryptography Alice encrypts her bit with a random key Sends to Bob At a later time, she sends Bob the key He can then verify the bit Disadvantage: Alice may be able to generate another key so that the bit is changed once she knows the result.
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}