Hash-Based Authentication Revisited in the Age of High-Performance Computers

Hash-based authentication is a widespread technique for protecting passwords in many modern software systems including databases. A hashing function is a one-way mathematical function that is used in various security contexts in this domain. In this paper, we revisit three popular hashing algorithms (MD5, SHA-1, and NTLM), that are considered weak or insecure. More specifically, we explore the performance of the hashing algorithms on different hardware platforms, from expensive high-end GPUs found in data centers and high-performance computing centers to relatively cheaper consumer-grade ones found in the homes of end-users. In parallel, we observe the behavior of different hardware platforms. Our results re-emphasize that despite their theoretical strength, the practical utilization of widely used hashing algorithms are highly insecure in many real-world scenarios; i.e., cracking a password of length 6 takes less than 6 seconds using a consumer-grade GPU.