Nano 101: Epoch Blocks

Everything you need to know before next week’s launch

Since all accounts on the Nano network are asynchronous, we need an asynchronous form of chain upgrades. Unlike Bitcoin, we’re not able to say “upgrade at block X,” so as a solution, the team developed Epoch blocks.

Next week, our team will begin the process of distributing Epoch Blocks across the Nano network. Because this is a unique method of upgrading the network, let’s take a look at this new, special block type.

What are Epoch blocks?

Epoch blocks are the final stage of the Universal Block network upgrade and designate the end of the Legacy block (send/receive/change/open) era. Upon the addition of an Epoch Block to an account-chain, old-style blocks added to the account-chain will no longer be validated by the node software.

Following Epoch Blocks:

An account-chain can no longer generate legacy blocks.

Any transaction following the epoch block on the account-chain must be received by a state block.

How are Epoch blocks being distributed?

Functionality for Epoch blocks was added in version 15, specifically, Pull Request #955. All Epoch blocks are signed by the Genesis account and will be added to each account-chain on the network, as well as to all un-opened accounts with pending receives.

Because of the large number of frontiers on the network, the Proof of Work is being generated using the Distributed Proof of work system developed by The Nano Center. All Proof of work is being done on our side; users will not need to generate any themselves.

What can Epoch blocks change?

As an account-chain upgrade, Epoch blocks move accounts on the network from Epoch 0 to Epoch 1. Any future transactions will have a minimum version of 1, which cannot be received by Legacy blocks and when received by a State block, automatically upgrades the account to version 1.

Epoch blocks are unable to change any balances or representatives on accounts. If an epoch block did attempt to change the balance of an account, the node would reject it because the signature would be incorrect, as only the account-chain holder can sign blocks which change balances or representatives.

Epoch blocks are planned as a one-time use, however, could be used in future upgrades if deemed necessary.