Have you heard about the new update from Solana called Alpenglow? This is a pretty serious change that should speed up the work of the blockchain by 100 times. Instead of the current 12.8 seconds, it will take only 150 milliseconds to finalize the block.
In fact, this means that transactions will be confirmed almost instantly, and this will affect the entire ecosystem: from dApps to payment solutions. But along with this acceleration, there are some compromises.
What is Alpenglow?
This is a hard fork that completely changes the Solana consensus system. The Proof of History (PoH) mechanism is currently being used, which marks blocks with time so that all validators are synchronized. Together with it, the BFT Tower works, a confirmation system that ensures that the majority of network participants come to an agreement.
With Alpenglow, both of these mechanisms will become a thing of the past. They will be replaced by two new ones:
Rotor — accelerates the distribution of blocks across the network. It uses the Turbine architecture already familiar to Solana, but makes block delivery easier and faster, with a minimum of intermediate steps.
Voter — is responsible for finalizing the blocks. A block is considered confirmed if 80% of the validators voted for it in the first round. Or if at least 60% in the first and the same amount in the second. This reduces the number of re-approvals that used to slow down work.
Why is this necessary?
Now Ethereum is actively developing and implementing scalable solutions like sharding. If Solana does not improve performance, it may lose ground.
Alpenglow is the answer to the challenges of the times. Moreover, Solana wants to develop its PayFi concept, a fast, decentralized system for mass payments that can compete with Visa and Mastercard. And without lightning-fast confirmation of the blocks, this idea simply won't take off.
How does it work?
The trick is that most of the work on the distribution and verification of blocks is now transferred outside the blockchain. In other words, there will be less load on the network itself, and blocks will be confirmed in a fraction of a second.
Each validator will sign blocks with BLS certificates, which are secure and lightweight digital signatures that are easily and quickly verified.
What is the result?
Block completion in 150 ms (compared to 12.8 seconds now).
The fixed block time is 400 ms, which makes the network stable and predictable.
Commissions are reduced — more transactions per second → lower block load → lower price.
The network is scaling up — more applications, more users, without congestion.
PayFi — Solana support is moving towards creating a blockchain-based payment system.
But everything is not so clear
Alpenglow reduces the level of acceptable failure. Previously, Solana could work even if up to 49% of validators were compromised (the so-called 51% rule).
Now the new mechanism can fail up to 40%: 20% can be hacked, and another 20% can simply log off the network. This simplifies the system, but makes it more susceptible to attacks and failures.
Question
Alpenglow provides a huge boost in speed and scalability, which can make Solana a truly global platform for payments and decentralized services. But all this is achieved by partially losing resilience to failures and attacks.
So is it worth pursuing instant transactions if you have to sacrifice some of your security for it?
