Kusama CC-2: PrePoS

Gavin Wood
Polkadot Network
Published in
3 min readOct 26, 2019


Kusama just got an upgrade

If you’re not already familiar with the concept of a runtime upgrade, it is a feature of meta-protocol-based blockchain technology (of which Polkadot/Substrate is one of only two that I’m aware of) allowing the blockchain to autonomously, atomically and instantly upgrade from one version of itself to another, generally obviating the need for a hard-fork. This ability to upgrade the system in situ, which is quite common in software these days, allows us to incrementally evolve our systems, adding new features over time, even as the blockchain is deployed and in production.

This upgrade, catchingly named 1005, takes us within spitting distance of moving to a fully nominated proof-of-stake (NPoS) network. It introduces a couple of interesting new features:

The biggest feature introduced is the change in its internal cryptography. In Polkadot/Kusama, transactions are signed using public/private key cryptography (PKI). Up until now, Kusama has allowed two variants of cryptography scheme based on the Edwards 25519 curve (Ed25519 and Ristretto). Unfortunately both of the x25519 schemes are relatively recent technological advances, and hardware wallets are not always the most up to date. As such, with this upgrade, we introduced the ability for transactions to be signed not just with the Edwards schemes, but also with the older SECP256k1 curve (using the ECDSA scheme) which enjoys broad hardware signer support as it’s the cryptography used in both Bitcoin and Ethereum. So Kusama now has three cryptography options open to you.

If you’ve read some of the other articles on Kusama and Polkadot, you’ll be aware that Kusama comes with a fairly substantial governance framework. A key part of this framework is the Kusama Council, a body of individuals (technically individual accounts), which act as a collective to help steer the evolution of Kusama and to determine how its resources are deployed. So far all functionality of Kusama except the ability to present oneself as a staker has been disabled. As of this upgrade the Council elections module has been enabled, essentially meaning that it’s now possible to both submit one’s candidacy and be elected to the Kusama Council. The venerable Polkadot JS will shortly be updated to facilitate the process of submission for becoming a Kusama councillor.

If all goes well in the meantime, we expect to make the final move to Kusama PoS next week, beginning with 50 validator slots and increasing to 100 and beyond as we become increasingly confident over the stability of the networking and consensus. Once upgraded to PoS, the Sudo “training wheels” (letting Web3 Foundation step in and rescue the network if needed) will be removed and Kusama’s decentralised governance will be in full force. The Kusama token will be freely transferrable between accounts.

For more information on Kusama, visit its website, use the network with Polkadot JS, see the code at the Polkadot Github repository, view the v0.6.3 release notes, or see the network in action over the telemetry service.