Sibos 2025: How Public and Permissioned Networks are Converging

0:00 – Adi Ben-Ari:

Welcome to what I believe is the first panel of the event. A warm welcome, and thank you for attending. We have a very exciting panel this morning to kick things off. I’ll let our speakers introduce themselves one by one. Redwan, would you like to start?

0:26 – Redwan Meslem:

Thank you. Hi, good morning everyone. I’m Redwan, Executive Director of the Enterprise Ethereum Alliance. We’re a non-profit promoting Ethereum adoption in large enterprises. We’ve been around since 2017 and focus on education, supporting Ethereum’s growth for enterprise, and developing standards.

0:48 – Daniela Barbosa:

I’m Daniela, Executive Director of the Linux Foundation Decentralized Trust. For over 25 years, the Linux Foundation has been home to some of the world’s most important open-source projects. Most of the technology you used on your way here today was likely built within our ecosystem.

Ten years ago, we started our blockchain project — originally called Hyperledger, now the Linux Foundation Decentralized Trust — which hosts over 17 active projects. Open source and open development are critical to this industry. I’m very pleased to be here at Sibos and look forward to the conversation.

1:33 – Biswarup Chatterjee:

Good morning everyone. Thank you for joining us. I’m Biswarup Chatterjee from Citi, based in New York. I manage innovation and partnership activities across our services and organizational teams.

1:45 – Tony McLaughlin:

Hi everyone. I’m Tony McLaughlin. I spent 30 years in traditional finance before deciding to work on public blockchains. It’s great to be here.

1:59 – Adi Ben-Ari:

Thank you. I’m Adi Ben-Ari, Founder and CEO of Applied Blockchain. We’ve been building blockchain solutions for about 10 years. Before that, I worked at Lloyds Banking Group. Over the years, we’ve explored many blockchain applications and recently developed Silent Data — a Layer 2 Ethereum platform that brings privacy to banking and financial use cases.

To kick things off, Tony will help set the scene for our discussion.

2:47 – Tony McLaughlin:

I was asked to frame the question of public versus private — or more precisely, permissionless versus permissioned — blockchains.

Let’s go back to first principles: what problem are we trying to solve in financial services? Every financial institution is, at its core, a balance sheet. One of your key functions is recordkeeping — maintaining your own assets and liabilities.

There’s recordkeeping within your firm, and there’s recordkeeping between firms when customers transact. These transactions ultimately come down to the movement of assets and liabilities between balance sheets.

So, what’s the best way to handle recordkeeping internally and across institutions?

Today’s dominant model is messaging. At Sibos, we’re surrounded by messaging networks — SWIFT, for example, is essentially a secure structured email service. Each institution maintains its own records and sends structured messages to others.

Blockchains present a different model: shared, synchronized ledgers instead of point-to-point messaging.

So the question is — what’s the best way to run the system? Do we stick with messaging? Do we use private blockchains? Or do we embrace public blockchains for shared recordkeeping?

4:49 – Adi Ben-Ari:

Thank you, Tony. Biswarup, can you tell us a little about how the bank has approached this from the start?

4:58 – Biswarup Chatterjee:

Thanks, Tony. When I look at private versus public blockchains — or even beyond blockchain, just messaging systems — I think of public as discovery and private as comfort and trust.

You use public networks to find information and participants. Think of how you use the open internet to search for information. In contrast, private spaces are where trust and confidentiality matter. Information is restricted, data is privileged, and participants are known and verified.

For example, trusted messaging systems like SWIFT are designed so that only specific recipients can see the information.

As you gain familiarity and confidence in the ecosystem, you might expand your participation — that’s where a public-permissioned middle ground begins to emerge.

It’s about maturity and business models. When we operate bilaterally with clients in trusted environments, that’s private space. But as ecosystems mature, both public and private systems start to converge.

5:00 – Adi Ben-Ari:

And what’s the attraction of public ledgers?

5:07 – Biswarup Chatterjee:

Think about information dissemination. Today, if you want to know where a stock is trading, that’s public information — it’s available to everyone. But if you want details about a specific transaction and who was involved, that’s not public.

These layers can coexist. You can operate within a public ecosystem while carving out more controlled zones within it. I don’t see them as separate technologies — it’s about taking an existing network and defining your level of openness.

You can have a public network with private, permissioned areas inside it — what I call “comfort zones.” That’s how I see the future: public ecosystems with embedded privacy and control.

8:00 – Adi Ben-Ari:

Thank you. Daniela?

8:06 – Daniela Barbosa:

I agree. Public infrastructure brings tremendous value. I was looking back at when banks first experimented with public blockchains. It was 2017, when BBVA in Spain originated a loan on a permissioned blockchain — I believe it was Hyperledger Fabric — and recorded it on Ethereum. That was groundbreaking.

I remember being in meetings with banks where we’d mention Ethereum or Solidity, and executives would say, “We don’t talk about public blockchains here.” But the developers in the room — our community — were the ones asking us to talk about it. They understood the potential.

At the Linux Foundation, we wanted to be the home for enterprises to safely experiment and build. Early on, there weren’t enough engineers or regulatory clarity. Things have improved since then, but full clarity is still missing.

We’ve always seen convergence coming. On one side, you had the “crypto crowd,” and on the other, enterprise executives. I thought enterprises would move toward public systems — and we’re now seeing that happen. At the same time, the public ecosystem is moving toward the center through Layer 2s and privacy subnets.

Why? Because financial use cases demand it. Banks and institutions require privacy, compliance, and interoperability — and those needs are pulling both sides closer together.

Public blockchains enable liquidity and composability. Running private networks and consortium systems was expensive — maintaining all that node infrastructure adds up. Public infrastructure lowers those costs while providing global liquidity and shared rails. Without public networks, you can’t achieve true liquidity or scalability.

10:45 – Adi Ben-Ari:

Redwan, over to you.

10:48 – Redwan Meslem:

Thank you. To frame the public versus private question, I’d focus on three things: neutrality, resilience, and liquidity.

You can create private chains or closed ecosystems, but when you do that, you often rebuild the same silos that already exist in traditional finance. If we want to optimise financial flows, we need access to liquidity — and that liquidity exists on public infrastructure.

When you use blockchain, the goal is to make money by optimising those flows, moving assets faster and more efficiently, while staying compliant. The more you rely on open, public systems, the less dependent you are on intermediaries operating the network for you.

Look at Ethereum: it’s been around for 10 years, has undergone 16 major upgrades, and moved from proof-of-work to proof-of-stake without downtime. It’s battle-tested, globally distributed, and constantly maintained by an independent developer community.

This is true resilience — a network that never stops running because thousands of teams around the world maintain it simultaneously. If one client fails, others pick up the load. These engineers are obsessed with neutrality, reliability, and performance.

At first, it might feel risky to build on something without a central operator — there’s no “President of Ethereum” or direct SLA. But what you gain is a neutral, transparent, and proven infrastructure that’s more resilient than any single organisation could offer.

On top of that, Layer 2 solutions now make it possible to build semi-private environments directly connected to the liquidity of Ethereum. So you can have privacy and performance without losing access to the broader ecosystem.

In short — if you want to grow your business and access liquidity, the biggest opportunities are on public, composable networks.

13:42 – Adi Ben-Ari:

Thank you, Redwan. That’s a great segue.

If I think about our own journey at Applied Blockchain, for the first few years we advised clients to start with private Ethereum networks — a controlled sandbox for testing. It gave enterprises the comfort of control while learning the technology.

But we always encouraged them to stay ready to connect to public ecosystems when the time came. That’s exactly what’s happening now.

We won’t go too deep into technical details, but Layer 2s are a key bridge here. They allow organisations to maintain privacy and performance while remaining connected to public liquidity. It’s where the convergence is happening.

15:00 – Adi Ben-Ari:

Tony, let’s talk about use cases.

15:05 – Tony McLaughlin:

I’d like to reframe the question slightly. We often speak as though each bank can choose which technology to use — public or private — but I see it differently.

Ethereum is a place.

Your customers are transacting there. The same goes for Solana — it’s a place where customers already operate.

If you, as a bank, don’t show up in those places, your customers will use someone else who does.

When you look at your customers’ transactions and see money flowing from your balance sheet into an exchange, that’s a clear signal — they’re going somewhere you’re not.

If your bank doesn’t have a stablecoin on Ethereum, your customers are using USDC or USDT. If you don’t have tokenised deposits on Solana, they’re using someone else’s product.

These networks are markets — and the real question is whether you want to serve your customers where they already are.

I understand the hesitation. Regulators have made these places feel risky for banks to engage with. But if your customers are transacting on Ethereum, you have to be there, just as you’d open a branch on a busy high street where your customers shop.

It’s not a technology choice. It’s a question of market presence — do you want to meet your customers where they transact, or lose them to competitors who will?

16:55 – Adi Ben-Ari:

That’s a powerful analogy. Redwan, you had an example that illustrates this shift?

17:00 – Redwan Meslem:

Yes. This morning, I needed liquidity. I had ETH, but not enough cash in my bank account to cover a payment. So I used a DeFi protocol to borrow against my ETH at around 5% interest for a week — enough to pay my credit card bill.

It took minutes. There’s no traditional bank that can offer that kind of instant, composable liquidity.

It might sound like a niche case, but that’s exactly why people are using DeFi. It gives them flexibility, faster settlement, and lower cost.

17:45 – Biswarup Chatterjee:

That’s an interesting point, and it ties into how institutions and regulators think about these systems. There’s an ongoing debate: are blockchains technology platforms or marketplaces?

If they’re just technology, then you regulate the entities using them, not the networks themselves. But if they function as marketplaces for liquidity, then they fall under market regulation frameworks.

It’s still early days — institutions and regulators are still defining what a blockchain network really is.

At Citi, our Stablecoin 2030 report explores this. It notes that money must remain safe, sound, and fungible, and that privately issued money — like stablecoins and deposits — must stay interoperable with the broader financial system.

Ultimately, banks need to be present in these ecosystems. Otherwise, we risk missing business opportunities as money and liquidity move elsewhere.

20:00 – Adi Ben-Ari:

Daniela, you’ve seen this space evolve. How do you view the convergence that’s happening between public and private systems?

20:10 – Daniela Barbosa:

We’ve all been waiting for that “killer use case,” and stablecoins are definitely one of them. They’ve shown how tokenised money can function in real systems.

The other big driver is interoperability — the progress we’ve made connecting networks. It’s becoming critical. There won’t be one blockchain to rule them all, but there will be winners and losers, and enterprises need optionality. That’s what they want most.

If you’d asked me ten years ago whether enterprises would be where they are today, I’d have said no way — they move too slowly. But what’s happened is a B2C push: consumers are driving the market forward, and institutions are following.

The convergence of public and private ecosystems is being powered by two things: interoperability and privacy technologies.

On privacy, advances in zero-knowledge proofs and confidential computing are beginning to make public systems viable for financial use cases. These tools are still early-stage, but they’re evolving quickly.

At the Linux Foundation Decentralized Trust, one thing I’m especially proud of is bringing regulators into the conversation. We now have nine central banks participating, including the Bundesbank. They’re sitting at the same table as the builders and developers, shaping what comes next.

That collaboration between regulators, developers, and innovators is key. If we all work together, we can move fast — but safely and compliantly — while meeting consumer demand and maintaining trust.

24:40 – Adi Ben-Ari:

That’s a great point. Collaboration between regulators and builders feels essential for what’s coming next.

25:00 – Adi Ben-Ari:

Redwan, is there going to be one blockchain to rule them all?

25:12 – Redwan Meslem:

I don’t think so. What I do know is that right now, about 60% of stablecoins and 85% of DeFi activity are on Ethereum.

I completely agree with Daniela — we’re seeing a real shift in behaviour and mindset across the Ethereum ecosystem. There are now dedicated teams focused on engaging with enterprises, listening to their needs, and helping them integrate.

Even the Ethereum Foundation has made it a key priority to improve performance, user experience, and enterprise collaboration. Leadership has been very open about that.

This is a huge change from just a couple of years ago. We now have a team within the Foundation dedicated entirely to enterprise engagement — something that didn’t exist before.

The message is simple: whatever challenge your enterprise faces, there’s a global open-source community ready to work with you to find a solution.

27:10 – Adi Ben-Ari:

Thank you. Tony — this is the first session of the conference. As everyone heads into the next few days, what should they be thinking about?

27:20 – Tony McLaughlin:

I’ve been thinking about the most provocative statement I could make to start Sibos. Here it is:

The bank account is dead.

A bank account is just a window into a private ledger — your internal database. Customers get limited access to it through online banking interfaces.

But if we’re moving into a world of tokens, then everything changes. Customers will hold tokenised deposits, stablecoins from regulated issuers, and tokenised money market funds — all accessible through wallets, not accounts.

These tokens will live across multiple chains, and wallets will become the new interface for financial interaction.

Competition will no longer be about who holds the account — it’ll be about who provides the wallet.

We’re entering an era defined by tokens, chains, and wallets. That’s where the future of finance is headed.

28:55 – Adi Ben-Ari:

On that note, we’ll let it rest there. Thank you very much, everyone.

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