Since the launch of open staking in May this year, we’ve seen tremendous growth of interest for staking on Harmony network. Nearly 4 billion ONE tokens are being staked across a total of 86 unique validators and the numbers are still growing. As the first Proof-of-Stake protocol with sharding, we strive to simplify the staking flow and provide the best user experience for our stakers. We’ve also been paying attention to the community’s feedback to make sure our community’s concerns are taken care of in time.

In the early days of the staking launch, we experienced instability of the validator network and our users are not quite familiar with the system, causing many tokens locked in inactive validators and having to wait for 7 epochs before they can be delegated to other validators. Many of our community members requested to shorten the 7 epochs locking period believing it’s not fair to get punished this way at the early stage of network launch. After an off-chain proposal and sentiment polling, we’ve decided to temporarily reduce the undelegation locking period from 7 epochs to 0 epoch until the validator dynamics settle. The proposal and discussion can be found here.

Restore the 7 Epoch Locking Period

Now that the network has been running stable for months and most of the validators are settled with their strategy and positions, it’s time to bring back the 7-epoch locking period to fully enforce the network security as originally designed. Additionally, to reduce the friction of switching validators and promote a fairer chance for new validator to compete with established validators, we are introducing the new feature of token redelegation, which allows undelegated tokens to be used for delegations without having to go through the 7 epoch locking period! With this, it will be less risky for stakers to try out new validators who may have lower commission fees but are not yet tested for stability. Redelegation and 7-epoch locking period will be enabled at epoch 290 which happens around Friday 10PM PST, September 25th 2020.

Undelegated tokens are available for delegation after the epoch of undelegation

Redelegation with Locked Tokens

Redelegation is introduced without adding extra complexity to the existing staking flows. There isn’t another transaction type specifically for redelegation. Everything works the same way as before, besides that the new delegations will try to utilize the locked tokens first and, if not enough, the liquid tokens from the users wallet. Note the locked tokens are only available for redelegation after the epoch when they were first undelegated. This is to make sure the tokens can still be slashed within the same epoch of undelegation if they are used for malicious double signing.

Specifically, if stakers want to redelegate X tokens from validator A to validator B, they can first undelegate the X tokens from validator A and the tokens will be locked immediately. After the end of the epoch, they can send a delegate transaction with X tokens to validator B and the locked tokens will be immediately unlocked and used for the new delegation. Alternatively, If the delegation amount is greater than the locked tokens that’s available for redelegation, the liquid tokens will be used to fill the difference.

With the restoration of 7 epoch locking period and the newly introduced redelegation support, we are bringing back the security guarantee of the original EPoS model without significantly affecting the existing stakers’ workflow. For more discussion and proposal about Harmony network, feel free to write a post at https://talk.harmony.one/.