Notice on the Tokyo Hard Fork
This page explains how the consensus mechanism migration (PoA → PoSA) affects the supply of JOC.
1. Overview of the Tokyo Hard Fork
Japan Open Chain (JOC) will carry out a large-scale network upgrade, the "Tokyo Hard Fork", to improve the network's medium- to long-term stability and transparency and to strengthen its technical compatibility with Ethereum.
With this upgrade, the consensus mechanism migrates from the current Proof of Authority (PoA) to Proof of Staked Authority (PoSA). PoSA combines a consensus mechanism based on the Proof of Stake (PoS) used on Ethereum Mainnet with a consortium-style governance model in which, as before, only approved organizations can participate as Validators.
This does not mean that anyone can freely become a Validator, as on Ethereum Mainnet. The basic network governance, in which the JOC consortium manages Validators, is maintained.
The upgrade mainly delivers the following three things:
- Validator operation based on economic incentives ― A mechanism is introduced in which Validators receive rewards in JOC for operating the network, such as producing blocks and participating in consensus.
- Automated on-chain penalty mechanism ― To economically encourage proper Validator operation, reward reductions and Slashing are applied at the protocol level according to uptime and misbehavior in consensus. This adds economic security that the previous PoA did not have.
- High technical compatibility with Ethereum Mainnet ― By aligning the consensus layer with Ethereum's PoS architecture, it becomes easier to follow Ethereum's technical standards and future upgrades.
In addition, more of the network, such as Validator registration and reward management, will be managed on-chain. The Tokyo Hard Fork is positioned as an upgrade that strengthens economic security and operational transparency while maintaining the existing consortium-style governance.
2. Impact on JOC supply and the reward model
With the Tokyo Hard Fork, the JOC supply and the Validator reward mechanism will change. Under the current PoA, no new JOC is issued for producing blocks or similar activities. After the migration to PoSA, new JOC will be issued as protocol rewards for Validators producing blocks and participating in consensus.
As a result, JOC moves from a supply model with no new issuance to a supply model with very small, continuous new issuance. However, the amount of new issuance relative to the total supply is extremely limited. The expected issuance, assuming 25 Validators, is as follows:
| Item | Value |
|---|---|
| Total JOC supply | 1,000,000,000 JOC |
| Annual new issuance | Approx. 8,814 JOC |
| Annual increase relative to total supply | Approx. 0.00088% |
| Cumulative supply increase over 10 years | Approx. 0.0088% |
JOC also burns part of the Base Fee charged on transactions. At the current level of network usage, however, the amount burned is negligibly small compared with the amount of new issuance.
Although the Tokyo Hard Fork moves JOC to a supply model with very small new issuance, the resulting supply increase is extremely small relative to the total supply. We therefore believe the impact of this supply increase on the market price of JOC will be extremely limited.
The JOC that Validators stake is existing JOC transferred to the Deposit Contract, not newly issued JOC. Staking itself therefore does not increase the total supply of JOC.
3. Impact on JOC holders and DApps
The Tokyo Hard Fork is an upgrade of the network infrastructure centered on the consensus mechanism. It does not exchange or migrate existing JOC or user assets to a new token. The following are maintained after the upgrade:
- Existing chain data
- Past transaction history
- The JOC Chain ID (81)
- Existing JOC
- How existing DApps and wallets are used
Therefore, there is no Token Swap or Token Migration, no change to the JOC Contract Address, and no change to balances. Existing data is not reset, assets are not moved to a new chain, and the RPC Endpoints do not change. In principle, DApps and general JOC holders do not need to take any special action.
The economic impact on existing JOC holders is the increase in supply caused by new JOC being issued as Validator rewards after the migration to PoSA.
As described above, with 25 Validators the annual increase is only about 0.00088% of the total supply, so the dilution for existing JOC holders is also extremely limited.
4. Conclusion
The Tokyo Hard Fork is a network upgrade that aims to strengthen economic security, operational transparency, and technical compatibility with Ethereum while maintaining JOC's consortium-style governance.
With this upgrade, new JOC will be issued as Validator rewards. However, the increase relative to the total supply is extremely limited at about 0.00088% per year, and we believe the impact of the supply increase on the market price of JOC will also be extremely limited. Because existing JOC, chain data, and usage environments are maintained, general JOC holders and DApps do not need to take any special migration steps.
If you have any questions about the Tokyo Hard Fork or the contents of this page, please contact us via the contact form.