In this paper we explore several contexts where an adversary has an upper hand over the defender by using special hardware in an attack. These include password processing, hard-drive protection, cryptocurrency mining, resource sharing, code obfuscation, etc.
We suggest memory-hard computing as a generic paradigm, where every task is amalgamated with a certain procedure requiring intensive access to RAM both in terms of size and (very importantly) bandwidth, so that transferring the computation to GPU, FPGA, and even ASIC brings little or no cost reduction. Cryptographic schemes that run in this framework become egalitarian in the sense that both users and attackers are equal in the price-performance ratio conditions.
Based on existing schemes like Argon2 and the recent generalized-birthday proof-of-work, we suggest a generic framework and two new schemes:
