NGRAVE ZERO: What That EAL7 Certificate Really Covers

The NGRAVE ZERO is a 398 dollar air gapped signer whose headline EAL7 claim describes an operating system kernel, not the finished device. The only public EAL7 Common Criteria result we could find belongs to ProvenCore, certified in 2019 on an Arm platform. The companion app, the QR channel and the update path all sit outside it.

On this page: the three different EAL7 claims NGRAVE makes in its own words, the only EAL7 record we could find in the public databases, today’s price and stock read from the vendor store, and four dated owner accounts from the ZERO subreddit.

What does the NGRAVE ZERO EAL7 claim actually cover?

Start with what the vendor says, because it says several things. Checked on 10 October 2026, the NGRAVE ZERO product page calls the device “the only air-gapped crypto wallet that achieved the highest security certification in the blockchain & financial industry”. A feature panel lower down narrows that to the “Only financial product that achieved EAL7 certification”. Another line narrows it again, to “a custom OS that achieved EAL7 certification”. The specification table simply lists the certification level as “CC EAL7, CE, RoHS, FCC”, which puts an operating system evaluation in the same row as a plug socket safety mark.

Those are three different claims, and the gap between them is the whole story. Common Criteria evaluations are granted to a named product at a named version against a written security target, and everything outside that boundary is unevaluated. Unevaluated is not the same as insecure. It is also not certified.

The number means less than it looks, too. EAL stands for Evaluation Assurance Level: it measures how rigorously something was examined, not how safe it turned out to be. EAL7 demands formal mathematical proof of the design, which is rare and hard. That is also why it lands on something small, like a kernel, rather than on a gadget with a battery, a fingerprint sensor, a camera and a phone app attached.

Is there a certificate you can read for yourself?

This is where the affiliate reviews stop and we kept going. NGRAVE’s pages give no certificate number, no scheme and no evaluated version, so there is nothing on them to look up. The only EAL7 Common Criteria result in the public record matching the description belongs to ProvenCore, a formally proven microkernel sold to device makers rather than a wallet. ProvenRun’s own certification page says that in 2019 “ProvenCore running on an Arm-based platform achieved Common Criteria EAL7”, and that “Reaching EAL7 requires formal verification to ensure the absence of design flaws”.

Read the rest of that page and the picture sharpens. A later ProvenCore evaluation on RISC-V reached EAL5+ and, by ProvenRun’s own account, no formal certificate was requested from the French scheme at all. ProvenCore-M, the microcontroller version, carries SESIP Level 3 rather than any EAL. Even inside the certified component, only one version is the EAL7 one.

Then we tried to read the certificate, which is where it gets awkward. The certificate PDF linked from ProvenRun’s own EAL7 announcement returned HTTP 404 when we fetched it on 10 October 2026, and a full text search of the Common Criteria database at sec-certs.org for “ProvenCore” returned no certificate entries the same day. The Common Criteria portal’s product listing refused our requests outright. None of that means the certification did not happen. It means a reader who wants to check the scope, which is the only thing a certificate is for, currently cannot. NGRAVE does not name ProvenCore on the pages we read, so we will not assert the link on its behalf: what we can say is that no certificate naming NGRAVE or the ZERO turned up in the databases we searched.

How does the ZERO compare with other air gapped signers?

Prices and stock were read from each vendor’s own store on 10 October 2026. The ZERO is the dearest of the four by a wide margin, and on the day we looked it was also the only one out of stock.

Two caveats, because being straight about them beats a tidy row. The Ledger Flex page rendered no price to our fetch, so the $249 figure comes from Ledger’s academy page rather than the live store. And an EAL6+ secure element is a chip certification, the same category of claim as an EAL7 operating system: one component, not the signer you hold. We made that point about the Trezor Safe 5 and the Ledger Flex too.

The Coldcard Q row is the instructive one. It carries no EAL claim at all, and it still had the worst summer of any wallet this year. Coinkite’s own advisory, published on 30 July 2026 and updated on 1 August, says seeds made on affected Mk4, Mk5 and Q firmware held “about 72 bits of entropy rather than the expected 128 bits”, and that “updating the firmware does not change or repair an existing seed”. A certificate would not have caught that bug, and the absence of one did not cause it. The fallout is in our Coldcard Q write up.

How many coins does the NGRAVE ZERO really support?

Here the product page argues with itself. On 10 October 2026 one feature summary on the ZERO page promises “+3 500 coins and tokens”, while a section headed “Broad Crypto support” on the same page says “We support 15 coins and all Ethereum and MultiversX tokens”. Both are true in their own way, which is the problem: one counts tokens on a few chains, the other counts the chains. Read the big number, hold a coin on a chain the device never supported, and you find out at the worst possible moment.

The release notes are the better guide, and they move. NGRAVE’s release notes page lists version 1.8 in August 2026 as current, with 1.7 back in October 2024. The 1.8 notes say it replaced the legacy QR format entirely with Universal QR, added the full Polygon token set plus PAXG, AMP and USDT on MultiversX, and put a warning screen before XRP and Stellar account closing transactions. They also say it removed “over 100 inactive, duplicated and legacy tokens” and that “BNB Beacon Chain and Groestlcoin (GRS) are no longer supported”, BNB on BNB Smart Chain unaffected.

None of that is scandalous. Pruning a token list is maintenance, not betrayal. It is simply the thing no certificate can speak to: support is a moving target, and the only way to check it is to read the release notes for the coins you hold.

What does closed firmware mean when you cannot read it?

The ZERO’s firmware is not published. Checked on 10 October 2026, the NGRAVE GitHub organisation holds libraries and forks: a UR registry, a token database, a trimmed libwally-core, a CBOR library, research papers, and forks of Rabby and MetaMask Mobile. Useful work, none of it the device operating system. So a claim about a formally verified OS is one you take on trust, rather the opposite of what a proof buys you.

Owners have noticed. On 24 April 2026, inside a thread about the company’s January 2026 restructuring, one owner asked when the firmware code would reach GitHub “to match your open source claims”. Nobody from the company answered there. The restructuring itself is on the record: NGRAVE’s support account posted on 15 January 2026 that the company “completed a strategic restructuring supported by a group of investors”, that the largest new party was Lydian Group, and that the main new investor is Luxembourg based. That is a fact about continuity, not a signal to move anything anywhere. If reading the code matters to you, our piece on what open source wallets actually prove sets out what you get, and the BitBox02 sits at the other end of that spectrum.

What do NGRAVE ZERO owners actually report?

We read four threads in the ZERO owners’ subreddit, roughly thirty comments, dated between November 2025 and August 2026. These are paraphrased accounts of what people report, not findings. The range runs from delighted to done with it.

• An update that failed mid flash. In December 2025 an owner described a ZERO that would not boot after an update, surviving four and a half hours of cables, ports, laptops and the manual flashing route. NGRAVE replied in the thread the same day and replaced the device free of charge. The recovery backup was intact, so the cost was time.
• Battery and bulk, as a daily annoyance. In January 2026 an owner wrote that the device drains in the safe and has to be fetched and charged, and that signing means carrying it, so they were moving to a different setup and selling two units.
• A calm answer to the Coldcard scare. On 1 August 2026, the day after Coinkite’s advisory, an owner asked whether the ZERO was exposed to the same seed generation bug. Another replied that there was no evidence of it, different firmware and different key generation.
• The vendor’s reply, two days later. On 3 August 2026 NGRAVE’s support account wrote that the ZERO draws 256 bits of entropy from a hardware random number generator plus the fingerprint reading and the owner’s interactions, does not rely on one entropy source, and that it recommends a passphrase regardless of wallet. It called the EAL7 operating system “the highest security certification available for this type of component”, narrower wording than the product page uses.

Where the accounts and the official story agree: support answers, and fast. Where they part: the marketing sells a certified device, while the risks in these threads were an update that bricked a unit, a battery, and an unanswered question about published code. None of those is what an EAL7 proof is about. All of them are what owning the thing is about. One vendor line is worth repeating, because it is the only universal advice here: a passphrase on top of the recovery words protects you even if the words leak. Read how a recovery phrase works first, because a passphrase you forget is indistinguishable from a wallet you destroyed, and nothing legitimate will ever ask you to type those words into a website, an app or an email.

So is the certificate worth anything?

Yes, narrowly. A formally verified kernel is a real achievement and better than no kernel assurance at all. It does not cover the companion app, the QR channel, the fingerprint sensor, the battery, the shipping chain or the update path, and in the accounts above it was the update path that bit. So when a review calls a certificate proof of the safest wallet in the world, ask which product and which version the certificate names. A page that cannot answer has not read the document it is selling you. Our guide to what a cold wallet does and does not do makes the longer case, and the Keystone review shows a cheaper air gap.

Frequently asked questions

This article is educational and is not financial advice. Nothing here is a recommendation to buy, sell or hold anything, and Theo Brandt holds no financial qualification. Speak to a qualified professional about your own situation. Security claims were verified on 10 October 2026 against the sources linked above.