Efficient Window-based ECC with Precomputation and Multitasking for In-Vehicle Communication

Abstract

In recent years the flourishing development of Internet of Vehicle (IoV) makes its security more important Elliptic Curve Cryptosystems (ECC) that is the popular cryptograph nowadays only requires 256-bit keys to achieve the same level of security as RSA requiring 3072-bit keys However most development IoV boards like NXP MPC5748G perform ECC-based algorithms too slowly to meet IoV real-time requirement due to resource-constraints and algorithm’s complexity Especially the drivers may fall into danger if vehicular devices are unable to communicate in real-time In order to achieve fast in-vehicle communication we propose an efficient window-based Elliptic Curve Cryptosystem augmented with precomputation and multitasking By analyzing the reusable points needed in the scalar multiplications of ECC-based algorithms like public-key generation Elliptic Curve Digital Signature Algorithm (ECDSA) and Elliptic Curve Diffie-Hellman (ECDH) we build Affine base-point table in the precomputation phase Moreover with the usage of multitasking the communications between devices are nearly unaffected when the board is processing the complex ECC algorithms and Jacobian public-key table is able to be built in the meantime As we know the fixed window and sliding window methods with non-adjacent form can simplify scalar multiplications We further apply Affine base-point table and Jacobian public-key table to these two window methods respectively and propose two new schemes fixed doubling-precomputation window method (fixed DPW method) and sliding doubling- precomputation window method (sliding DPW method) to nearly avoid the need of point doublings for achieving better performance As a result ECC’s performance can be improved to complete a single scalar multiplication in about 90ms which is a fifth of the time needed for the tradition scheme Even for the most time-consuming process of ECDSA_verification our improved approach takes about 400ms that is shorter than 500ms needed in the original approach Finally we also propose a fast scheme to update symmetric keys and private/public keys without ECDSA while providing Forward Secrecy By using our proposed schemes we are able to show that the in-vehicle networks can resist intrusion from man-in-the-middle attack replay attack and the leakage of symmetric keys to keep the communication secure

Date of Award	2020
Original language	English
Supervisor	Yeim-Kuan Chang (Supervisor)