Database System Concepts
7th Edition
ISBN: 9780078022159
Author: Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan
Publisher: McGraw-Hill Education
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An underground resistance group wants to write articles with completely differ- ent security goals. The resistance group shared a secret at the last resistance meeting that they can all use for these articles. Here are their goals:
- Only users with the shared secret should be able to upload to the server.
- Only users with the shared secret should be able to read the articles.
- Any changes to the article should still be easily detectable
- The resistance is paranoid about both quantum computers and any mod- ern encryption
algorithms so they want to avoid public key cryptography. They only trust AES (symmetric key encryption) and SHA-256 (crypto- graphic hashing) since these have been around for decades and are resistant to quantum computers.
- Write a protocol for the underground paper to authenticate authors before publishing to the server. (HINT: Make sure that this protocol cannot be tricked by someone who has been listening to the previous article upload)
- Write a protocol for the server to use to send out the published articles.
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