## Beyond ZisK: Can Its High-Speed Architecture Be Generalized for All zkVMs?

### A Research Deep Dive

A few weeks ago, the ZisK team unveiled a monumental achievement in the world of verifiable computation: a zkVM capable of generating a RISC-V execution trace at an astounding **$1.5{ GHz}$**. This leap, roughly an order of magnitude faster than existing solutions, was made possible by a brilliant architecture that sidesteps the traditional sequential bottleneck of trace generation. As detailed in our [previous article](https://hackmd.io/@0xdeveloperuche/rkd1vBsElx), ZisK achieves this through a two-step process:

1. **Ahead-of-Time (AOT) Compilation:** Translating a RISC-V program directly into optimized, native `x86_64` machine code.
2. **Minimal Trace Generation:** The fast native binary doesn't generate the full, heavy witness. Instead, it produces a lightweight "minimal trace" (a log of memory reads and register checkpoints) which then allows for massively parallel, memoryless re-execution by the provers.

This innovation was so profound it begged an immediate question: Is this a bespoke masterpiece, or a universal blueprint? Could this architecture be extracted and applied to other zkVMs in the ecosystem, like Risc Zero, SP1, or Jolt, to grant them a similar speed boost?

This was the research I set out to explore. The conclusion, after a deep dive into the ZisK codebase, is that while ZisK's approach is powerful, its magic lies in a deep, vertical integration that makes a universal, "plug-and-play" solution highly challenging to implement.

### The Core of ZisK's Engine: A Custom Compilation Pipeline

To understand the challenge of generalization, we must first appreciate how deeply customized the ZisK execution flow is. It's not simply a matter of running a standard RISC-V binary through a special emulator. The process starts much earlier.

1. **A Custom Rust Target:** The journey begins when a developer compiles their Rust code. The ZisK team forked the standard `riscv64ima` Rust compiler target to create their own: `riscv64ima-zisk-zkvm-elf`. This custom target modifies the compilation process itself, producing an ELF file that, while structurally similar to a standard RISC-V ELF, contains what can be described as **"ZisK-flavored" bytecode**. This is the first and most critical point of divergence from a standard toolchain.

2. **From ZisK Bytecode to Instrumented x86 Assembly:** The next step is the `rom-setup` process. This is where the core of the AOT compilation happens. A component within the ZisK tooling reads the custom ZisK ELF bytecode and translates it, instruction by instruction, into native `x86_64` assembly.

This is not a simple, direct translation. The true genius of the system is that during this process, the compiler **injects additional `x86_64` instructions** responsible for generating the minimal trace. For every RISC-V instruction that reads from memory, the compiler adds the necessary `x86_64` code to log that read value to the `Memory Read Log`. It's a masterful piece of engineering that weaves trace generation directly into the fabric of the executable code itself.

The key insight is this: **ZisK achieves its speed by controlling the entire compilation pipeline, from high-level Rust code all the way down to the final machine code executed by the CPU.**

### The Quest for a Universal "ZisK-ifier"

With this understanding, the path to generalizing this architecture for other zkVMs becomes clearer, as do the immense hurdles. Two potential strategies emerged.

#### Path 1: A Universal ZisK ISA

The most straightforward path would be for all other zkVMs to adopt the ZisK Instruction Set Architecture (ISA) and its custom toolchain.

* **Feasibility:** This is almost certainly not going to happen. zkVMs like Cairo and Miden have developed their own custom ISAs (Cairo Assembly and Miden Assembly) specifically tailored to be "SNARK-friendly" and optimize their respective proof systems. Risc Zero and SP1 are built around the standard RISC-V ISA for broad compatibility. Forcing these established ecosystems to re-platform around a new, specialized ISA is a non-starter.

#### Path 2: A Universal Translator

A more realistic, albeit far more complex, approach would be to build a universal translator. This tool would theoretically take a standard compiled binary from another zkVM (e.g., a standard RISC-V ELF from Risc Zero) and apply the ZisK AOT compilation trick to it.

This would involve:

1. **Forking a Compiler Backend:** One would need to work at the lowest levels of the compiler stack, likely by forking the LLVM backend.
2. **Transpiling ISAs:** The tool would need to translate instructions from the source ISA (e.g., standard `RISCV32IM`) to the target `x86_64` ISA.
3. **Injecting Trace Logic:** This is the crux of the problem. The tool would need to be intelligent enough to inject the *correct* `x86_64` assembly to generate the minimal trace. This logic is not universal; the specific data that needs to be traced is tightly coupled to the constraints of the *destination proof system*. The trace required by Risc Zero's STARKs is different from what a different system might need.

Building such a tool requires a rare and deep expertise in compiler design and low-level systems engineering. It represents a significant research project in its own right, with a steep learning curve and no guarantee of a truly universal outcome.

My research leads to a clear conclusion: **ZisK's phenomenal speed is not the result of a modular plugin but of a holistic, deeply integrated, and customized architecture.** The tight coupling between its custom Rust target, its bespoke bytecode format, and its instrumented AOT compiler is the very source of its power.

This finding itself is a valuable result. It demonstrates that while the dream of a one-size-fits-all "zkVM accelerator" is compelling, the frontier of performance in the ZK space is still being pushed by architecture-specific innovation. The path to faster, more efficient zkVMs lies not in finding a single silver bullet, but in the specialized engineering of vertically integrated systems, just as the ZisK team has so brilliantly demonstrated. The solution is elegant and inspiring, but its replication across the ecosystem is, for now, a monumental challenge.