From its initial announcement back in April to the $430,000 raised in the recently completed crowd-sale, the NGRAVE ZERO has created huge buzz in the crypto community. Billed as the most secure hardware wallet available, the permanently air-gapped ZERO is the first to gain a top security rating of EAL7.

But the devil is in the details so they say, so while waiting for the first units of the device to ship, Cointelegraph asked NGRAVE CEO Ruben Merre to explain just how one goes about making the “most secure hardware wallet in the world.”

Necessity is the mother of invention

The ZERO came about following the NGRAVE founders’ poor experiences with crypto security. Not finding any existing solutions that they would completely trust with their cryptocurrency, they set about building their own.

In April 2018 the team began to develop a working prototype using a Raspberry Pi. It was the start of a journey which would see them collaborate with many world class teams and individuals, including the recent acquisition of Jean-Jacques Quisquater as an advisor.

Quisquater is considered the father of zero knowledge proof cryptography, and is famously cited in the Bitcoin whitepaper. So what does he bring to the development of a secure hardware wallet?

“Jean-Jacques is closely involved in revealing and resolving potential security threats, even those that are on practically no one else's radar. Because he was involved in the development of the many security projects including those by secret government instances, he knows backdoors as no other. He's also one of the minds in our team that helps us think future-proof.”

No man is an island… but the NGRAVE ZERO is

Much has been made of the fact that the ZERO remains fully air-gapped, eschewing USB and Bluetooth connectivity to communicate solely via QR codes which contain no data about the users private keys.

Also, private keys generated by the wallet’s Perfect Key system are not derived purely from a “master-seed” shipped with the device. For extra security they incorporate elements of biometric data such as fingerprints and the introduction of environmental randomness from factors such as light levels.

This might leave you wondering how you will import your existing cryptocurrency private keys onto the device, and whether they will be as secure as freshly generated ones.

“We support all the available ‘status quo’ ways of generating seeds, so you can both import a mnemonic phrase made with another hardware wallet, regardless of the length, or you can also simply create a new one on ZERO. While we recommend using the NGRAVE Perfect Key because of its advanced security features, the user can basically choose what he or she feels most comfortable with.”

Can’t touch this

Finally, in case anybody gets their grubby little mitts on your physical device, the ZERO has four different cumulative levels of tamper-proofing.

The first is tamper resistance, including shielding of radio frequencies, and the physical difficulty of gaining access to the device's innards.

Then comes tamper evidence, which means that if anyone does manage to break open the device, the screen will break and it will be apparent to the user. It also incorporates cryptographic attestation, whereby NGRAVE will verify a device on first use.

“The third level is called "tamper responsiveness". This means there are mechanisms in place inside the device that will notice that it is under attack. And ZERO will then automatically wipe the keys. This goes as deep as on the level of individual components that have their own anti-tamper mechanisms.”

Finally, there is tamper resolution, which takes place when the user is manipulating the private key in the aforementioned generation process. This results in the resolution of any potential tampering or pre-defined keys in the device.

Cointelegraph will get hands on with the device as soon as it starts shipping to bring you a full review.