Title: Towards Secure Communication and Authentication: Provable Security Analysis and New Constructions

Shan Chen

School of Computer Science

College of Computing

Georgia Institute of Technology

Date:  Wednesday, January 8th, 2020

Time: 12:00 - 2:00 PM (EST)

Location: Coda C1008 Bolton

Committee:

Dr. Alexandra Boldyreva (Advisor), School of Computer Science, Georgia Institute of Technology

Dr. Mustaque Ahamad, School of Computer Science, Georgia Institute of Technology

Dr. Vladimir Kolesnikov, School of Computer Science, Georgia Institute of Technology

Dr. Paul Pearce, School of Computer Science, Georgia Institute of Technology

Dr. Gaven Watson, Advanced Cryptography, Visa Research 

Abstract:

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Secure communication and authentication are some of the most important and practical problems studied in modern cryptography. Plenty of cryptographic protocols have been proposed to accommodate all sorts of requirements in different settings and some of those are widely deployed and utilized in our daily lives. For instance, over half of web traffic is now protected by the Transport Layer Security (TLS) protocol to encrypt the communication between web servers and clients. Not surprisingly, these real-world protocols are hot targets of malicious attacks, which could lead to disastrous confidential information leakage and significant financial loss. It is therefore a crucial goal to provide formal security guarantees of such protocols.
 

In this thesis, we apply the provable security approach, a standard method used in cryptography to formally analyze the security of cryptographic protocols, to three topics related to secure communication and authentication. We first focus on the case where a user and a server share a secret and try to establish a session key for secure communication, for which we construct the first user authentication and key exchange protocols that can tolerate strong corruptions on the client-side. We next consider the setting where a public-key infrastructure (PKI) is available and propose a model to formally compare the security of the most important low-latency secure channel establishment protocols: TLS 1.3 over TCP Fast Open (TFO), QUIC over UDP, and QUIC[TLS] (a new design for QUIC that uses TLS 1.3 key exchange) over UDP. Finally, we perform the first provable security analysis of the new FIDO2 protocols, the promising proposed standard for passwordless user authentication from the Fast IDentity Online (FIDO) Alliance to replace the world's over-reliance on passwords to authenticate users, and design new constructions to achieve better security.