VDF Wrapper

---

This repository contains a go wrapper for VDF implementation in rust(taken from https://github.com/poanetwork/vdf)

Usage

Build

• On linux based OS:

make build

• On macOS:

make buildmacos

Testing

This will run the tests listed in vdf_test.go which cover the basic testcases of generating and verifying

make test

Benchmarking

Generating the performance benchmarks

make bench

• generate and verify testcase:

Version         |   Difficulty   |  Operations  |   NanoSeconds/op  |   Bytes/op    |   Allocs/op   |
----------------|----------------|--------------|-------------------|---------------|---------------|
Wrapper(Rust)   |   100          |  1           |   1427637682      |   1632        |   4           | 
                |   1000         |  1           |   1666627794      |   1632        |   4           |  
                |   10000        |  1           |   2283725710      |   1632        |   4           |
                |   100000       |  1           |   8857166929      |   1728        |   5           |
----------------|----------------|--------------|-------------------|---------------|---------------|
Go              |   100          |  2           |   776854280       |   322415756   |   3154336     | 
                |   1000         |  2           |   2526245854      |   2698829064  |   26177189    |  
                |   10000        |  2           |   17168590230     |   22612145312 |   221400958   | 
                |   100000       |  1           |   158626758580    |   216820251240|   2131684085  |

• verify testcase with 100 difficulty

Version         |   Difficulty   |  Operations  |   NanoSeconds/op  |   Bytes/op    |   Allocs/op   |
----------------|----------------|--------------|-------------------|---------------|---------------|
Wrapper(Rust)   |   100          |  2           |   772468279       |   576         |   1           |
----------------|----------------|--------------|-------------------|---------------|---------------|
Go              |   100          |  3           |   373219950       |   95635781    |   946215      | 

Analysis

• Time taken per operation - Time taken for verification is of the similar order. In case of generate, as the difficulty increases the time taken by the wrapper version is significantly less than that by the go version. For a difficulty of 10000, time taken by the go version is around 17 seconds. However the wrapper version takes only 3 seconds which is similar to the time taken by the pure rust library for the same inputs

• Memory per operation - Both the metrics bytes used and allocations show that the wrapper version is significanlty better than the go version

Profiling

There are tests written in vdf_test.go which test the generate and verify functions for both this wrapper version and using the go version. In order to create the cpu and memory profiles, run:

make prof

This will generate the CPU and memory profiles for the tests. In order to visualize these profiles:

• install Graphviz(https://graphviz.org/download/)
• this will create png files for the profiles
• for samples, see profile001.png for cpu and profile002.png for memory

Integration

The file vdf.go exposes a public function New(difficulty int, input [32]byte) which can be used to initialize a VDF. The Execute function can be used to run the created VDF and Verify function can be used to verify the proof

With the Harmony client(https://github.com/harjas27/harmony/tree/use_rust_vdf)

This repository exposes the similar functions to create, execute and verify as done by the https://github.com/harmony-one/vdf repo. All the public functions have been implemented with the same signature as that to the current go VDF repo. Thus, by changing the imported go module, this repo can be integrated with the client An integration with the harmony client that builds successfully can be found here - https://github.com/harjas27/harmony/tree/use_rust_vdf