Harrell, Nicholas and Krakauer, Nathaniel, "Closing the Gap: Leveraging AES-NI to Balance Adversarial Advantage and Honest User Performance in Argon2i" (2023). CERIAS Technical Reports. Paper 3.
Date of this Version
cryptography, hardware optimization, argon2i, key derivative function, kdf
The challenge of providing data privacy and integrity while maintaining efficient performance for honest users is a persistent concern in cryptography. Attackers exploit advances in parallel hardware and custom circuit hardware to gain an advantage over regular users. One such method is the use of Application-Specific Integrated Circuits (ASICs) to optimize key derivation function (KDF) algorithms, giving adversaries a significant advantage in password guessing and recovery attacks. Other examples include using graphical processing units (GPUs) and field programmable gate arrays (FPGAs). We propose a focused approach to close the gap between adversarial advantage and honest user performance by leveraging the hardware optimization AES-NI (Advanced Encryption Standard New Instructions). AES-NI is widely available in modern x86 architecture microprocessors. Honest users can negate the adversary advantage by diminishing the utility of their computational power. We explore the impact of AES-NI on the Argon2i KDF algorithm, a widely-used and recommended password hashing function. Through our analysis, we demonstrate the effectiveness of incorporating AES-NI in reducing the advantage gained by attackers using ASICs. We also discuss the security and performance trade-offs to provide guidelines for practical implementation in deployed cryptosystems.