Cryptology ePrint Archive: Report 2017/1074

A Practical Fault Attack on ARX-like Ciphers with a Case Study on ChaCha20

S V Dilip Kumar and Sikhar Patranabis and Jakub Breier and Debdeep Mukhopadhyay and Shivam Bhasin and Anupam Chattopadhyay and Anubhab Baksi

Abstract: This paper presents the first practical fault attack on the ChaCha family of addition-rotation-XOR (ARX)-based stream ciphers. ChaCha has recently been deployed for speeding up and strengthening HTTPS connections for Google Chrome on Android devices. In this paper, we propose differential fault analysis attacks on ChaCha without resorting to nonce misuse. We use the instruction skip and instruction replacement fault models, which are popularly mounted on microcontroller-based cryptographic implementations. We corroborate the attack propositions via practical fault injection experiments using a laser-based setup targeting an Atmel AVR 8-bit microcontroller-based implementation of ChaCha. Each of the proposed attacks can be repeated with $100\%$ accuracy in our fault injection setup, and can recover the entire 256 bit secret key using 5-8 fault injections on an average.

Category / Keywords: implementation / ChaCha, ARX cipher, Laser, Fault Attack, Instruction Skip, Instruction Replacement

Original Publication (in the same form): FDTC 2017

Date: received 5 Nov 2017

Contact author: sikhar patranabis at iitkgp ac in

Available format(s): PDF | BibTeX Citation

Version: 20171110:152618 (All versions of this report)

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