The power and limits of preprocessing in cryptography

Placeholder Show Content

Abstract/Contents

Abstract
Preprocessing refers to a computation that is executed before one is given the inputs to a certain computation task. Preprocessing can be used to speed up some cryptographic systems but also to speed up cryptanalytic attacks. This thesis explores the power and limits of preprocessing for both of these goals. First, we study algorithms with preprocessing for some of the most central problems that underpin the security of modern-day cryptosystems. We give new lower bounds for generic algorithms with preprocessing for the discrete-logarithm, CDH, and DDH problems. We also present new connections between the task of inverting functions with preprocessing and other areas of theoretical computer science. These connections shed light on the gap between the best known upper and lower bounds for the function-inversion problem and give rise to better algorithms for well-studied problems in complexity theory and data structures. We then turn to using the power of preprocessing to construct new protocols for private information retrieval. Our protocols allow fast (sublinear-time) private database lookups without increasing the server-side storage requirements. Finally, we present Checklist -- a system that uses these protocols for private blocklist lookups. In Checklist, a client can determine whether a particular string appears on a server-held blocklist, without leaking its string to the server. We implement and evaluate Checklist in the context of the "Safe Browsing" blocklist, which all major browsers use to prevent web clients from visiting malware-hosting URLs.

Description

Type of resource text
Form electronic resource; remote; computer; online resource
Extent 1 online resource.
Place California
Place [Stanford, California]
Publisher [Stanford University]
Copyright date 2021; ©2021
Publication date 2021; 2021
Issuance monographic
Language English

Creators/Contributors

Author Kogan, Dmitry
Degree supervisor Boneh, Dan, 1969-
Thesis advisor Boneh, Dan, 1969-
Thesis advisor Reingold, Omer
Thesis advisor Wootters, Mary
Degree committee member Reingold, Omer
Degree committee member Wootters, Mary
Associated with Stanford University, Computer Science Department

Subjects

Genre Theses
Genre Text

Bibliographic information

Statement of responsibility Dmitry Kogan.
Note Submitted to the Computer Science Department.
Thesis Thesis Ph.D. Stanford University 2021.
Location https://purl.stanford.edu/sn383mk8063

Access conditions

Copyright
© 2021 by Dmitry Kogan
License
This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).

Also listed in

Loading usage metrics...