PowerVerify Attested — Cryptographically Signed Power-Only USB-C Interface

Preorder — $150, charged today · In development · Target ship: mid-August 2026

This is a paid preorder for a product still in development. You're charged $150 at checkout. We're targeting mid-August 2026 to ship. That's a target, not a guarantee — hardware in development can slip. If we can't meet it, we'll tell you, give you a revised date, and you can take a full refund at that point — or anytime before your unit ships. You're funding the final board work and first production run, and we'll keep you posted on exactly where the build stands.

Core lets you see there's no data path. Attested lets you prove it.

PowerVerify Core makes the data lines physically absent — and lets you verify that with your own eyes. PowerVerify Attested adds the next thing a forensic, legal, or procurement context needs: a way to prove, to someone who wasn't in the room, that a specific session happened on a specific device with no data path — without trusting ZKNOT, the host, or the operator.

Every power session is signed by a secure element on the device itself. The result is a record any third party can re-check against a published key, offline, with no central authority to trust.

What Attested adds over Core

• A hardware secure element (ATECC608B). Generates its key pair on-device; the private key never leaves the chip and can't be extracted in software.
• Signed power-session records. Each session is signed in hardware: device identity, start/end timestamps, measured voltage and current, and an attestation that no data path was active. The signature covers all of it — change any field and verification fails.
• Measured, not assumed. An onboard current/voltage monitor (INA219) records the real power profile of the session, not a nominal label.
• Third-party verifiable, offline. Anyone with the device's public key can verify a session record without contacting ZKNOT, without the device present, and without network access. Trust comes from the math, not from us.
• Tamper-evident history. Session records are hash-chained — each links to the one before it — so deletion or alteration of a past record is detectable.
• Anti-replay. A monotonic counter advances with every session, so records can't be reused or backdated.
• Pairs with ZKey (roadmap). Designed to share a session identifier with the ZKey human-presence signer, so a single verifiable record can prove both that power was delivered with no data path and that a human authorized the event in the same session.

The honest boundary — what a signed session does and doesn't prove

This is the upgrade over Core: Attested signs on the device, in the field, not just at our bench. So a verified session record is real cryptographic proof that this identified device recorded a power session with these measured parameters and no active data path.

What it does not claim: it isn't proof of what a charged device did internally beyond drawing power, and we don't market it as a legal guarantee of anything. It's designed for evidentiary and chain-of-custody workflows; how a given record is used in a proceeding is for the people running that proceeding to decide. We'll always tell you exactly what a claim is and what it isn't.

How verification works

1. A session ends; the secure element signs the session record.
2. The signed record is retrieved from the device.
3. A verifier checks the signature against the device's published public key and confirms the hash chain and counter.
4. The result is independently re-checkable — by you, by a recipient, by an auditor — without trusting the website, the host, or us.

Intended specifications (in development — subject to change)

• USB-C power-only path: D+/D− and SuperSpeed pairs physically absent; VBUS/GND pass through; CC pins for power negotiation
• 5–20V DC USB-C Power Delivery pass-through
• STM32G0B1 microcontroller · ATECC608B secure element · INA219 current/voltage monitor
• ECDSA P-256 signatures; on-device key generation, private key never exported
• Hash-chained, monotonic-counter session records
• Solid clear-resin potting with unique optical fingerprint, photographed and recorded at manufacture
• Serialized; records verifiable at verifyknot.io and from the published public key
• Patent Pending — U.S. Application No. 63/961,118 (additional applications pending)
• Designed in Utah · veteran-owned (SDVOSB) · Made in USA

Who it's for

People who must prove something to others, not just protect themselves: digital-evidence and chain-of-custody work · investigators and attorneys · journalists and researchers in adversarial settings · labs and secure facilities · procurement teams that need verifiable device provenance and session integrity.

If you only need to protect your own device while charging, PowerVerify Core is the right product and it's available now. Attested is for when a third party has to believe you.

Preorder terms

• Charged today. Your $150 is collected at checkout — this is a preorder, not a free reservation.
• Target ship: mid-August 2026. A target, not a guarantee. Hardware in development can slip.
• Full refund if we slip or you change your mind. If we miss the target window we'll notify you with a revised date and your option to refund in full. You can also cancel for a full refund anytime before your unit ships.
• What you're funding. Final board revisions, firmware, secure-element provisioning, and the first production run.
• Early-backer pricing. $150 is the preorder price; retail will be higher after launch.
• Limited slots, so we can build and support a small first batch well.