Intro
Bitcoin Cash is deciding on its next network upgrade. The headline proposal is CHIP-2025-03 Faster Blocks, which lowers the target block time from 10 minutes to 1 minute. Each block would carry 1/10th of the reward and 1/10th of the size limit, so per hour the economics stay the same: the same coins are issued, the same throughput fits, and the halving dates stay where they are.
The ParyonUSD project supports it. Back in our 2025 development update we called faster blocks likely the biggest win for DeFi on Bitcoin Cash, and we still think so.
Faster confirmations
The main reason we think 1-minute blocks are the biggest win for DeFi is race conditions. When several users act on the same contract at the same time, only one of their transactions can go through, and until the next block nobody knows for sure which one it was. With 1-minute blocks, that uncertainty clears in about a minute instead of ten.
With 10-minute blocks, waiting more than half an hour for a confirmation is not uncommon: 5% of waits take that long. After the upgrade, the same 5% take more than 3 minutes, and a half-hour wait practically never happens.
What it means for redemptions
Every ParyonUSD redemption waits 12 blocks before it can be finalized. Assuming steady hashrate, 90% of redemptions today take between about 1 and 3 hours. After the upgrade, those 12 blocks become 120 one-minute blocks (more on that below), and 90% land within about 20 minutes of the 2-hour mark.
The bigger gain is what happens during that wait. Redemptions go to the loan with the lowest interest rate, and the wait gives a borrower who pays a proper rate the time to have a wrongly targeted redemption moved to the right loan. That only works if their transaction gets mined, so what protects borrowers is how many different miners find a block in that time. With 120 blocks instead of 12, nearly every sizable mining pool gets a turn, which makes it much harder to keep a transaction out.
Is a 1-minute block less secure?
A common objection is that a 1-minute block holds 1/10th of the proof-of-work of a 10-minute block. That’s true, but what matters is whether it makes reversing a payment easier.
Joemar Taganna, who leads Paytaca, initially withheld support over exactly this concern. After working through the math in an independent analysis, he changed his position to approve:
The PoW arithmetic is still correct: a single 1-minute block contains 1/10th the chainwork of a 10-minute block. However, in a minority-attacker scenario it doesn’t matter, because at the same number of confirmations the reversal probability depends only on the count, not on chainwork. On the other hand, in the majority-attacker scenario it does matter: redoing the work of one 1-minute block costs 1/10th that of a 10-minute block, but the chainwork needed per minute is unchanged, so just requiring ten 1-minute block confirmations erases that difference.
In the end, I realized what really mattered was whether a 1-minute block results in so much less security that even minority attackers could easily double-spend transactions with 1 confirmation. This turned out not to be the case.
A service that keeps waiting the same amount of time loses nothing. What’s new is the option to wait less when less is at stake: 1, 3 or 10 one-minute blocks, instead of choosing between zero confirmations and a full 10-minute one. Services moving large amounts should raise their confirmation counts to match.
What happens to our timelocks
ParyonUSD’s contracts measure time in blocks, and they can’t be changed. That doesn’t mean our redemption delay shrinks to 12 minutes. Under the CHIP, a block-based timelock keeps meaning “this many 10-minute units”, so our 12-block delay becomes 120 one-minute blocks: still about 2 hours. The CHIP even uses our redemption delay as an example: without this rule, contracts already on-chain would unlock up to 10 times early.
The same holds for every timer in ParyonUSD:
| Timer | Today | After the upgrade | Roughly |
|---|---|---|---|
| Redemption delay | 12 blocks | 120 blocks | 2 hours |
| Interest period | 144 blocks | 1,440 blocks | 1 day |
| Stability pool epoch | 10 periods | 10 periods | 10 days |
The contracts don’t change, and no migration is needed. What we do update is our app and backend services, which currently count in raw blocks. That will be done well before May, and our chipnet deployment gives us six months to test it against real 1-minute blocks.
What faster blocks don’t do
Faster blocks are not instant finality, and unconfirmed transactions remain the fastest way to pay on Bitcoin Cash. There are costs too: block headers grow 10 times faster, which matters for light wallets, and with less time for blocks to spread across the network, orphaned blocks become more common. The CHIP models an orphan rate of 0.4% to 1.9%, within its 2% tolerance, so occasional one-block reorgs become somewhat more common.
The road to activation
The main concern in the statements thread is whether the implementation will be ready in time. It is getting into very good shape, with review from several people, including Jason Dreyzehner, and a lot of AI-powered review. We’ve contributed to that too: with AI help we reviewed the CHIP in depth and have been going through the node’s code changes, and we’ll keep doing so through testnet.
Faster blocks have already activated on tempnet, a test network now running 1-minute blocks, and the CHIP is on track to lock in on November 15, when chipnet upgrades. Mainnet activation follows on May 15, 2027, which leaves six months for testing, and for the ecosystem to prepare.
We think faster blocks make Bitcoin Cash better for its users, and for DeFi in particular. We’re glad to add our support.
Join the Conversation
What do you think of 1-minute blocks? Let us know.
- Follow ParyonUSD on X: x.com/ParyonUSD
- Join the ParyonUSD group on Telegram: t.me/ParyonUSD
In our Telegram group you can engage directly with the team - ask questions, share your thoughts, and be part of the ongoing conversation as we build ParyonUSD together!