Croatian engineer Nino Doko has spent three decades recovering data in more than 50,000 ransomware cases. The lesson he’s drawn is clear: any data that’s connected is at risk. Three years ago, he decided to build something that couldn’t be reached, no matter how clever the attacker. The result is HyperBunker, an offline vault designed as the last line of recovery when everything else has failed.
The principle is simple. Storage that is never connected to a network can’t be stolen, corrupted, or encrypted by outsiders. HyperBunker achieves that using optocouplers – tiny devices that pass information one way via light – combined with a hardware buffer.
“Our customers run apps like manufacturing controls, finance systems, or customer databases,” investor and advisor Matt Peterman told Resilience Media. “HyperBunker protects the underlying repositories – once data is pushed, it’s locked and immutable. That removes the risk of that data being encrypted.”
Simply, data can be written in, but there is no route back out: no logins and no remote access.
“Even if you say it’s only online for a few seconds, that’s still enough for an attacker,” Doko told Resilience Media. “As long as you control the system with software, it means somebody else can control it too.”
Doko compares HyperBunker to a submarine airlock: one door must close before the next opens, and the two doors are never open simultaneously. That makes the final storage invisible to the network, and by extension, to would-be attackers.
HyperBunker is now building a military-specific version of its vault, adding features expected in the field, including a ruggedised enclosure, passive cooling, hardened I/O, removable media, and tamper-evident logging. The core architecture is the same as the civilian model, which has already shipped to early adopters in utilities and critical infrastructure.
HyperBunker’s first production run sold out, and with the next builds underway, defence buyers are moving through their own assessments.
It’s not hard to see the appeal. Ransomware gangs typically target backups first, and the cloud, once touted as a safe haven, is usually the first thing their automated scripts probe. HyperBunker sidesteps the game of cat and mouse by putting the crown jewels out of reach: each unit stores four versions of a dataset, giving operators the option to roll back if more recent snapshots are compromised.
For military users, the logic is hard to ignore. If a business loses data, it loses money, but if the military loses data, it loses lives. “In defence, you cannot wait in a queue for cloud support during a blackout,” Doko said. “You must hold your data under your own control.”
The question of ransom payments inevitably comes up. HyperBunker’s stance is clear: paying the hackers fuels crime, but bans don’t bring systems back online. The only reliable way to avoid being cornered is to hold an offline, immutable copy under your own control. Once attackers get administrator credentials – and most breaches end that way – they can access anything run by software. But even with a general’s password in hand, HyperBunker’s disks remain unreachable.
The design avoids features that often become liabilities. There is no cloud dashboard, no password-protected portal, no remote update mechanism. For IT managers used to everything being software-defined and API-driven, that may look primitive. For militaries facing persistent, well-resourced adversaries, it looks more like common sense.
Doko even argues it is quantum-ready. “If quantum computers break encryption, what can they do against storage that is never online?” he said.
HyperBunker, as you can see in the team picture above, is still a small outfit, closer to a startup than a prime contractor. But the first units have already shipped, the pipeline is full, and MoD evaluations are in progress.
“We have had great investor interest and expect to announce fundraising this fall from multiple investors,” Peterman said. “That will also help us in faster shipping of our hardware to clients.”
Peterman added that the company sees “complacency” as its biggest competitor, noting that organisations continue to trust online backups that ransomware actively targets. He said that others in the offline data storage market, such as Firevault, are not “truly offline” due to their reliance on internet-based management.
HyperBunker’s gamble is that in an age of drones and hypersonics, militaries won’t forget the basics: keeping a copy of their data truly offline. “A cybersecurity chain is only as strong as its weakest link,” Doko said. “That’s why we built HyperBunker to sit outside the chain. Even if everything else fails, it still holds.”
