Qtum Core Is Leveling Up:

Merging Bitcoin Core 27.2, Bitcoin Core 28, Bitcoin Core 29 and Ethereum’s Pectra Advancements into the ultimate smart contract platform.

Qtum has always been about combining the best of Bitcoin’s security model with the flexibility of Ethereum-style smart contracts. Currently, Qtum is based on Bitcoin 27.1 and includes support for Ethereum’s EVMone. Our upcoming core upgrade continues that vision,  integrating major improvements from Bitcoin Core 27.2,  Bitcoin Core 28 and Bitcoin Core 29 and on the EVM side we are integrating key elements of the Ethereum Pectra suite.

This update will come into effect on Qtum block 5,483,000 (Around January 12th, 2026)

This post walks through what’s changing, why it matters, and what everyday users, stakers, developers, and node operators can expect.

Bitcoin Core updates implemented in Qtum 29.

Bitcoin Core 29 includes several behind-the-scenes improvements designed to make nodes more reliable, more private, and more consistent, important benefits that flow directly to Qtum’s UTXO layer.

Network Stack Changes: UPnP Removed, Now using NAT/PCP/NAT-PMP

Bitcoin Core completely drops the old UPnP auto-port-forwarding library and moves to an internal implementation of PCP / NAT-PMP.

Why it matters:

• More reliable automatic port forwarding for home routers

• Removes dependency on fragile third-party UPnP libraries.

• Helps nodes stay reachable >  healthier, more connected network

• Wallets benefit indirectly because a stronger node network = faster, more reliable transaction propagation

• Better Tor binding behavior

• Support for Unix domain sockets. This is a method on *nix machines to allow programs to talk internally without using the network stack

• More granular control of peer whitelist flags

Expected outcome:

• Stronger privacy options

• Better control for advanced node setups

• Fewer disconnect issues on non-standard/customised operating system configurations
  

Qtum Impact: This improves overall network resilience, especially for community node runners and helps sync the chain faster on core wallets. We expect that some folks running a node behind older routers to see better peering and with that connection speeds. 

More Info: 

Qtum Core has dropped the old, insecure, and often unreliable “Universal Plug and Play” (UPnP) auto-port-forwarding system and replaced it with the new Bitcoin Cores version of built-in support for “Network Address Translation Port Mapping Protocol” (NAT-PMP) and “Port Control Protocol” (PCP), two modern protocols designed for today’s home networks and ISP setups. This upgrade gives users safer and more consistent inbound connectivity by avoiding UPnP’s long history of vulnerabilities and inconsistent router implementations, while providing faster, cleaner, and more reliable port-forwarding through standardized, lightweight protocols. The result is a node that “just works” more often, syncs more smoothly, and is better prepared for modern networking environments—all with less code complexity and fewer hidden failures.

Better Orphan Transaction Resolution 

Nodes now fetch missing parents for orphan transactions from all peers that announced them.

Why it matters:

• Fewer stuck transactions

• More consistent mempool data across nodes

• Faster propagation, better network health

Qtum Impact:  Qtum already has a quick block time of 32 seconds, however this should still be a benefit when determining orphan transactions. This also helps us keep in sync with our UTXO bitcoin roots. 

More info: 

Previously, when a node received an orphan transaction (a transaction whose parent wasn’t known yet), it would only try to fetch the missing parent from the first peer that announced it, which often caused delays or failures if that peer was slow, overloaded, or faulty. With the new improvement, nodes now request the missing parent transaction from all peers who announced the orphan, dramatically increasing the chance of quickly retrieving it from a reliable source. This leads to faster transaction processing, fewer stalled orphans, and a smoother, more reliable mempool for users and wallets. 

Early Steps Toward More Flexible Mempool Policies

A new concept, ephemeral dust, allows a package to include a tiny zero-fee dust output, as long as it’s spent in the same package.

Why it matters:

• More flexible transaction design

• Better compatibility with future fee innovations

• Mainly a developer / miner upgrade, but good for long-term scalability

Qtum Impact: Qtum’s mempool is basically the waiting room where all transactions go before they’re added to a block. The mempool works like Bitcoin’s for security, but also simulates smart-contract activity like Ethereum, so only valid and properly funded transactions get in. These changes will help batch contract calls and should help with transaction costs, which are already quite low.

This hybrid design makes Qtum fast, secure, and reliable even when the network is busy.

More info: 

The mempool is a node’s temporary memory for unconfirmed transactions, where Bitcoin Core checks fees, validity, and policy rules before forwarding them to the network. Traditionally, the mempool has strict rules that block very small “dust” outputs and zero-fee outputs because they clutter the network and are often uneconomical to spend. The new idea of ephemeral dust introduces more flexibility by allowing a tiny, normally-disallowed dust output only if it’s immediately spent within the same package of transactions. Because the dust doesn’t persist in the mempool, it appears and is consumed instantly, it doesn’t create long-term clutter or spam. This opens the door to more advanced transaction constructions and future policy improvements while keeping the mempool clean and efficient for everyone.

Removal of libbitcoinconsensus

The old consensus library has finally been removed.

Why it matters:

• Less legacy code to maintain

• A cleaner, simpler codebase

• Reduces risk of obscure bugs, easier long-term maintenance

• Aligns Qtum with Bitcoin’s modern architecture
  
  

Qtum Impact: This opens the door for Qtum to plug into a cleaner, more complete upstream validation engine, making future upgrades, security, and tooling simpler and more robust.

This update puts Qtum apart from other UTXO based blockchains that have not updated to the latest Bitcoin Core. Projects that get stuck on old code bases will struggle to update in the future, as they are still dependent on old libraries.

More info: Qtum used the Bitcoin library (libbitcoinconsensus) that checked if individual transaction scripts were valid, which was helpful but limited compared to the new kernel engine. Bitcoin Core (and Qtum) is now moving to a much more powerful engine (libbitcoinkernel) that exposes the whole validation “brain” blocks, UTXOs, and full consensus rules instead of just scripts.

Qtum Core Build System: Now Using CMake

Like Bitcoin, Qtum is transitioning its build system to CMake, replacing legacy autotools.

What this means:

• Consistent with upstream Bitcoin industry standards

• Faster, more reliable builds

• Simpler cross-platform support (Windows/macOS/Linux)

• Easier for new developers to compile Qtum Core from source
  

This is a major quality-of-life upgrade for contributors and integrators.

How Ethereum's Pectra Enhancements Fit In

The Ethereum Pectra update consists of multiple Ethereum Improvement Proposals (EIP) bundled together into one update. When you look at a smart contract blockchain, there’s the blockchain layer, and a smart contract layer. In Qtum’s case, we use the EVM for smart contracts, but the blockchain layer is based on Bitcoin Core. Many of the updates Pectra offers are tied into the Ethereum blockchain. In Qtum’s case, we get the benefits of Bitcoin Core, and less value from the EVM updates. One point to consider is that Qtum has to hard fork constantly alongside Ethereum, it’s not Bitcoin Core that’s causing us to hard fork. 

There is however one update to the EVM that is interesting, EIP-2537

This one goes back to 2020 and took quite a while to make its way into the EVM. This EIP will provide benefits to Qtum directly. You can read about this EIP here:

EIP-2537: Precompile for BLS12-381 curve operations

This upgrade will allow for more efficient ZK-Rollups on Qtum, while strengthening the underlying encryption that keeps everything secure. This has a lot more impact than it sounds, as ZK-Rollups allow for some powerful layer 2 scaling solutions that can significantly improve throughput for all kinds of applications. Most notably trading, gaming, gambling, file hosting, and even cross-chain bridges, etc.

This upgrade really future proofs Qtum by giving it the ability to deploy the next generation of rollups. Without this EVM update, Qtum would not be a competitive smart contract platform. This update also keeps Qtum in line with what developers expect in an environment, they don’t want to downgrade and develop on an older stack, which can also lead to compatibility issues when they try to cross-deploy their applications on multiple blockchains.

Summary

This is Qtum’s 50th wallet release, keeping the project up to date with the latest Bitcoin and EVM developments. The features native to Qtum Core, like the Decentralized Governance Protocol, our modified Proof-of-Stake model, and our 32 second block target are all on a stronger foundation.

Our development team can now focus on some much needed ecosystem initiatives to increase the daily active users. With Qtum Core 29.1, the network stack is a lot healthier, especially for communicating with nodes. This will certainly help strengthen the decentralization of the chain, which is imperative for applications that can’t go down like bridges, DeFi, prediction markets, and so forth. 

With an upgraded network stack and more efficient EVM, things like efficient and secure ZK-rollups make sense. 

Qtum’s latest push in artificial intelligence has been making progress as well and will benefit from a better Qtum Core once the token is integrated into the ecosystem. To date thousands of people have downloaded the Qtum Ally application, and we’re only getting started with https://qtum.ai

To download this Qtum update, please see the official Github page:

https://github.com/qtumproject/qtum/releases