Reboot based framework for high-threshold cryptosystem

Agarwala, Disha

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https://hdl.handle.net/2142/113214 Copy

Description

Title

Reboot based framework for high-threshold cryptosystem

Author(s)

Agarwala, Disha

Issue Date

2021-07-19

Director of Research (if dissertation) or Advisor (if thesis)

Mohan, Sibin

Department of Study

Computer Science

Discipline

Computer Science

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• High threshold cryptosystem
• Mobile adversaries
• Proactive Secret Sharing
• Security

Abstract

Threshold cryptosystems eliminate a single point of failure by distributing the root of trust in applications like key management-as-a-service, signature schemes and encrypted data storage. However, existing threshold cryptosystems do not ensure availability when a malicious adversary corrupts more than half of the devices in the network. We present High Threshold Cryptosystem (HiTC), an iterative reboot-based framework for threshold cryptosystem that is resilient against a malicious mobile adversary that can corrupt up to all but one device in the network. With a careful design of rebooting devices, HiTC ensures that a sufficient number of honest devices are always available in the network to ensure that the system as a whole is always available. We also design a novel and efficient resharing protocol to protect secrets in the presence of a strong mobile adversary. We assess our security assumptions through case studies of real-world attacks and extensive measurements. We implement HiTC atop a distributed symmetric key encryption system and evaluate it using up to 18 AWS EC2 instances and up to 6 Raspberry Pis. Our evaluation using AWS EC2 instances demonstrates that HiTC is practical and incurs an average overhead of 20% over the baseline. Furthermore, the Raspberry pi setup performs poorly, but preliminary results prove that enhancement in implementation can help achieve better performance.

Graduation Semester

2021-08

Type of Resource

Thesis

Permalink

http://hdl.handle.net/2142/113214

Copyright and License Information

Copyright 2021 Disha Agarwala

Owning Collections