Grin Testnet 4 Launch Announcement

After several months in the oven, I’m happy to announce that Grin’s 4th Testnet has been launched! Although we can’t be 100% certain, we very much hope this is the last distinct testnet we’ll need before our Mainnet launch. Many thanks and congratulations to everyone involved, and we hope to keep the momentum going right up to mainnet.

It’s now more important than ever that we have as many nodes, miners and testers as possible to help us exercise the network, find obscure issues and hunt for security holes. If you’re planning on getting involved with Grin at launch now’s a great time to jump in and practice, with many parts of the system stable and things (more or less) working as they will on mainnet. If you’re interested in helping out, our build guide is a great place to start, and there’s always someone around on gitter to help with any issues you might have.

I’d also like to take a moment to shamelessly plug our Security Audit Campaign. We’re still far short of our goal, and need you or your organisation’s help to ensure Grin is as secure as possible at launch. Please help us spread the word as far and wide as protocol allows!

A (non-exhaustive) list of the main changes from T3 is listed below. Thanks again to everyone involved, and we hope to see our connected peer counts maxxed out from now until launch and beyond.

  • Proof of Work changes:
    – Switch from cuckoo cycle to cuckatoo cycle (a new cuckoo variant)
    – Placeholder ASIC Resistant (AR) and ASIC-friendly (AF) PoWs (subject to change for mainnet), with ASIC friendly being gradually phased in over two years. The intention is that AF should make up 10% of blocks at first and gradually increasing to 100% over two years via difficulty scaling.
    – ASIC Resistant: Cuckatoo 29
    – ASIC Friendly: Cuckatoo 30+
    – AR pow will be hard forked to maintain ASIC resistance, ASIC creators are encouraged to target Cuckatoo 30+
    – Further details can be found at:
  • Changes to grin-miner to support mining Cuckatoo 29+ on CPU and GPU
  • Fixes and updates to our Aggregated Signature library, which adds support for atomic swaps
  • Updates and additions to Bulletproofs, allowing for multi-party bulletproofs and a method of restoring wallet contents from seed quickly.
  • Initial work to support the lightweight Flyclient
  • Wallet support for BIP-32
  • Support for multiple accounts within the wallet
  • Much work on sync performance and robustness
  • Work on block and header processing performance

Please note that if you were previously running a T3 node, you’ll need to clear out all of your T3 data. This should reside in your ~/.grin directory, so please be sure this directory is empty before attempting to run T4.