Alex²

CraterLake is the state-of-the-art hardware accelerator for FHE, providing speedups of 5,000× over CPU on a broad range of applications. Building upon F1’s functional units, CraterLake introduces a novel architecture that significantly reduces on- and off-chip data movement.

I came up with the way computation is distributed across the chip (Sec. 4), designed the on-chip network (Sec. 5.3), and designed the KeySwitch hint generator (Sec. 5.2).

F1 was our initial proposal for an FHE accelerator. F1 proposes novel high-throughput FHE functional units, but suffers from excessive on-chip data movement that prevents it from scaling to large FHE application. As a result, F1 is about 5,000× faster than a CPU on small applications (similar to CraterLake), but only 400× faster on large ones, (11× slower than CraterLake).

I designed the first SRAM-only, fully-pipelined transpose unit (Sec. 5.1), which is a crucial component of F1’s novel FFT and automorphism units.

I created a programming language that uses prefix notation for amusement purposes: for example, a = (b + c) * d looks like = a * + b c d. Nitwit is imperative, strongly typed, and uses reference counting garbage collection. The Nitwit compiler procudes C code, which can then be compiled to an executable.

A partially retroactive priority queue supports adding and removing updates (here, insert and delete_min) on past versions of the data structure. Retroactive differs from persistent in that the effects of changing past operations propagate to the present (like in Back to the Future). I implemented the data structure proposed by Demaine, Iacono, and Langerman, which performs all operations in logarithmic time.

A top-down 2D game where you collect coins while avoiding beeing seen by guards. The area each guard sees (their visibility polygon) is comptuted in O(n log n).

A two-player platformer where players progress by cooperatively solving puzzles made out of logic gates. Implements real-time multiplier using WebSockets.

In Bulgarian, “Vali li?” means “Is it raining?” This website has the answer!