Bitcoin Privacy Tool Payjoin Gets $100K Boost from Maelstrom to Expand Wallet Adoption

Bitcoin developer Ben Allen has received a $100,000 grant from investment firm Maelstrom to further develop Payjoin, a privacy-enhancing Bitcoin transaction method that also improves network scalability.

The announcement, made on May 20, revealed that the funding will support Allen’s work on the Payjoin development kit, a project he co-leads with fellow developer Dan Gould.

What Is Payjoin?

Payjoin, introduced in Bitcoin Improvement Proposal (BIP) 78 by Nicolas Dorier in 2019, is a collaborative transaction method. Unlike standard Bitcoin transactions where only the sender provides inputs, Payjoin allows both sender and receiver to contribute inputs. This obfuscates typical transaction patterns and complicates blockchain analysis.

The result? Enhanced financial privacy and better transaction output consolidation, which contributes to improved Bitcoin scalability.

Grant Details

Maelstrom, a firm led by Arthur Hayes (former BitMEX CEO), is providing Allen’s grant in Bitcoin, paid monthly over one year. The approach is notably hands-off — with no strict milestones — giving developers the freedom to build at their own pace.

“We believe grantees may work better with freedom to work on what they wish, rather than being tightly controlled,” said a Maelstrom representative.

Main Objectives: Wallet Integration and Developer Support

The key goal of the grant is to increase wallet adoption of Payjoin. Allen stated that the funding allows him to focus full-time on:

• Building out benchmarks to help developers integrate Payjoin.

• Expanding test coverage for reliability.

• Simplifying implementation to minimize user-side complexity.

“The biggest step we can take for encouraging Payjoin adoption is simplifying the experience and moving the complexities mostly away from the user,” Allen explained.

Despite its promise, Payjoin presents technical challenges. It requires the receiver to be online and involves more complex communication flows compared to typical Bitcoin transactions.

Payjoin Developer Kit’s website. Source: Payjoin Dev Kit

Why It Matters for Bitcoin Privacy

Arthur Hayes emphasized the importance of improving privacy in Bitcoin, saying:

“The great thing about Payjoin is that even limited adoption breaks a key assumption used by surveillance firms — that all inputs in a Bitcoin transaction belong to the same person.”

In other words, the more Payjoin is used, the harder it becomes for chain analysis companies to trace user activity — even benefitting those not actively using the tool.

Aiming for Mainstream Wallet Integration

Maelstrom is setting its sights on open-source Bitcoin wallets as a key success metric for the project. According to the firm, getting Bitcoin Core — the reference client — to adopt Payjoin would be a major win.

“We’re keen to support more grantees in the privacy area,” Maelstrom said, and is actively looking for more developers with strong track records in Bitcoin privacy.

Outlook

With Maelstrom’s backing, Payjoin development is poised to accelerate. If wallet integrations follow, the protocol could play a crucial role in reshaping Bitcoin privacy standards — not only shielding individual users but also strengthening the network’s resistance to surveillance and analysis.

Even limited adoption could significantly disrupt data tracing models, making Payjoin one of the most practical advancements for privacy-conscious Bitcoin users.