Graduation Year


Document Type




Degree Name

Doctor of Philosophy (Ph.D.)

Degree Granting Department

Computer Science and Engineering

Major Professor

Attila A. Yavuz, Ph.D.

Committee Member

Mehran Mozaffari Kermani, Ph.D.

Committee Member

Jay Ligatti, Ph.D.

Committee Member

Xinming (Simon) Ou, Ph.D.

Committee Member

Mike Rosulek, Ph.D.

Committee Member

Kaiqi Xiong, Ph.D.


Digital signature, PEKS schemes, post-quantum cryptography


IoT systems often rely on low-end devices to send measurements to other parties and depending on the setting, unauthorized alteration and/or privacy violation of these measures can have catastrophic consequences (e.g., embedded medical sensors). Therefore, providing efficient authentication, integrity, and confidentiality in these settings is vital. While conventional cryptographic measures (e.g., ECDSA) can be used to meet these security requirements, despite their elegant design, they are often too computationally expensive for low-end devices. This is further exacerbated when security against quantum computers is taken into the account.

In this dissertation, we propose a series of new efficient conventional and post-quantum cryptographic schemes to meet the stringent requirement of such IoT systems. In the line of proposing efficient authentication schemes, we propose two signature schemes. Our first signature scheme is based on conventional cryptographic problems and utilizes the message encoding with cover-free families and special property of ECDLP-based functions to achieve significant performance gain as compared to its counterparts. The second scheme is based on post-quantum primitives and is achieved by extending one-time signatures to (polynomially bounded) many-time signatures, using the additively homomorphic properties of generalized compact knapsack functions. The new scheme achieves the lowest end-to-end delay among its counterparts which makes it suitable for low-end devices. As a step toward a fully post-quantum blockchain, we propose a Proof of Work (PoW) protocol that minimizes the advantage of a quantum miner. Our new protocol is based on the Hermite Shortest Vector Problem (Hermite-SVP) in the Euclidean norm and allows for a fast verify algorithm. To alleviate the hurdle of certificate communication and verification for low-end devices, we then present an identity-based and certificateless cryptosystems that are created using special key generation algorithms that harness the additive homomorphic property of the exponents to enable the users to incorporate their private keys into the one provided by the trusted third party without falsifying it. The new schemes achieve better computation efficiency and comparable communication efficiency as compared to their identity-based and certificateless counterparts. Lastly, with the aim of proposing efficient and highly-secure measures for secure remote data storage, we propose two lattice-based public key searchable encryption schemes with post-quantum security. To our knowledge, our schemes are the first instances of such schemes based on lattices that provide a post-quantum promise. Our first variant is based on NTRU lattices and provides a significant performance advantage and better end-to-end delay as compared to its existing counterparts. The second scheme, based on the LWE problem in the standard model, provides a better security as compared to its counterparts with a cost of an inferior performance. All of the proposed schemes are proven secure via rigorous security proofs and are implemented and open-sourced to allow for public testing and verification.