Blockchain: A Solution to IoT Cybersecurity Problems

I’ve had three coffees so far, and if you know me, then you know I’m fired up. I just returned from DefCon — still buzzing from the hardware hacking village (yes, I spent far too long scrutinizing IoT teardown sessions). And this subject has been banging around in my brain all week: How do we realistically secure our IoT ecosystem? It’s growing rapidly — frighteningly rapidly — and old-style cybersecurity models just aren’t working anymore.

Meanwhile, with the big vendors jumping around hollering AI-based threat detection! (rolls eyes), I think it’s time we get back to basics. What I’ve personally seen work in the wild. Yep. Blockchain.

But hold on before you roll your eyes, let me guide you through this. From my own war stories and years in the trenches. From Slammer to smart watches — I’ve seen it.

Security Risks in IoT

Let me say this to begin with — IoT Security is broken. I have worked in this field since the early ’90s. First job was network admin in 1993. Security was then largely about keeping things running, not locking them down. But now? We’ve crammed billions of cheap, insecure devices in every nook and cranny of our lives — homes, factories, hospitals, cars.

And the attack surface? It’s massive. Here is what I often see:

• Devices protected by default passwords (admin/admin — really?) and there were no OTA update mechanisms.
• Vendor backdoors (deliberate or otherwise)
• Bad or lack of encryption
• Centralized cloud endpoints that are single points of failure

I have lost count of how many times I have audited a deployment and discovered smart bulbs, smart thermostats, or even biometric scanners that all had gaping holes. Think of someone hacking a vending machine within the bank’s network and using that as a springboard — sounds ridiculous, but I’ve honestly seen it.

TL; DR for the busy people:

• More IoT networks = more attack surface
• Standard hardening process is often bypassed by IoT devices
• One target for attackers: Centralized control
• A weak or nonexistent identity/authentication system for devices

There needs to be a revolution in IoT security. Not a patch. Not another AV. It’s something to do with… trustlessness. And that’s the role of blockchain.

Device Authentication with Blockchain

Here’s the rub — we’ve been using usernames and passwords to lock down networked devices for decades now. But these are all human mechanisms. And in a machine-to-machine (M2M) world, they don’t scale — or secure — properly. Blockchain flips the model.

It assigns a unique, cryptographically verifiable identity to each device. Like a virtual VIN that can’t be spoofed. What does that mean in practice?

• Devices can prove their identities without a centralized server saying, “Yes, I know you.”
• The keys are tamper-proof and bound to a public ledger — if someone wants to impersonate or replay credentials, it’s GG
• No more shared secrets flying around the network
• Privacy can be wrapped up in zero-knowledge proofs or selective disclosure

Three regional banks recently brought me in to redesign their zero-trust architectures. One of the best solutions involved adding a blockchain layer to monitor, validate, and verify device interactions — specifically for ATMs, card readers, and POS systems that had previously been operating in the dark. Is it perfect? No. But it’s better than relying on a DNS entry and a MAC address.

Decentralized IoT Security

Such centralized systems are brittle. One artillery shell, one misaligned ACL, and the whole smart factory goes dark. Or worse — hijacked. But what if these devices could talk to each other in a truly secured fashion peer-to-peer, utilizing a distributed model of trust rather than a single patchy cloud API? Enter decentralized security enabled by blockchain.

Here’s how:

• Central server = honeypot for attackers
• Smart contracts can ensure pre-defined rules are followed between devices (Device A talks to only Device B during shift hours, etc.)
• Full transparency — immutable logs of all device actions
• When rules are broken, alert and respond automatically
• Removes the requirement of fragile certificate authorities

For a logistics client during a POC, we were able to put data from 100+ geo-tagged sensors in the blockchain allowing them to share data between their warehouses without a single cloud vendor they trusted. They encrypted their traffic, signed it with blockchain-based identities, and verified each transaction using smart contracts. The head of the IT department told me he slept better that week than he had in any week over the past year.

Oh, did I mention — no outages? None.

IoT Blockchain Solutions by PJ Networks

We don’t just believe in blockchain for IoT — we build it. At PJ Networks, we have been working with clients to secure IoT environments using blockchain-based identity and trust frameworks. Our suite provides solutions for:

• Blockchain IoT Security Architecture Design (Soup to nuts)
• Custom smart contract development and rule engines for device-side enforcement
• Distributed registries for extremely secure firmware update pipelines

My favorite implementation was around helping a smart city in Western India. We protected their traffic signal controllers — yes, those poppable little boxes at intersections — by using blockchain-boosted device IDs and secure comms. Before we took the reins, anyone with a laptop and 15 minutes could’ve wreaked havoc.

Did we add latency? Barely measurable.

Did we detect multiple unauthorized access attempts from devices within days of going live? You bet. And did the city also scale that same infrastructure across traffic management, smart lighting, and, eventually, public kiosks? Absolutely. And it’s still going strong.

Conclusion

The IoT ecosystem isn’t going to get smaller. We’re not reverting to stupid devices. Smart tech is everywhere — right in everything from your car key to your coffee machine. But smart does not always equal safe.

If you’re still relying on basic firewalls and access controls to protect complex IoT deployments, you are one zero-day away from disaster. We need better tools. More resilient frameworks. And despite all the hoopla — blockchain is actually one of the few technologies delivering on its promise in this area. To recap:

• Blockchain helps devices get tamper-proof identities
• Adds resilience with peer-to-peer authentication
• Decentralization eliminates single points of failure
• Smart contracts can automate behavior without human intervention
• Everything is logged. Nothing is invisible.

Yes, I’m excited. Perhaps because I watched this tech blossom — from buzzword to something I actually use in the field now. Perhaps knowing that real value comes from every time I deploy Blockchain for IoT security. Real protection. Not just jargon. If you’re an IoT deployment in finance, manufacturing, healthcare, or anything else, it’s time to think about security differently.

We’re here for that.

We’ve fought worms, reverse-engineered cracked firmware, and spent days swimming around PCAPs to decode breaches — all so you don’t have to. We at PJ Networks are available to secure your IoT network with the decentralized force of blockchain. Firewalls, routers, servers — we handle all that as well. Now, time for coffee 4.

— Sanjay Seth
Founder, PJ Networks Pvt Ltd
Writing about Cybersecurity since 1993
Uploading data from the past until October 2023