Published by NEXSIM LLC · Montana, USA · Updated September 2026
NEXSIM LLC is a technology company based in Montana, United States. It was founded in 2026 by Etonde Fael Synclair. NEXSIM builds infrastructure for identity, security, and document integrity.
The company's first product is District Seal — a cryptographic evidence layer for high-stakes signatures. District Seal is available at districtseal.com.
What is District Seal?
District Seal is a cryptographic evidence layer for signatures that get challenged. It produces a court-admissible certificate every time a document is signed. The certificate captures who signed, when, and on what device, and it binds the record to the exact document with a SHA-256 cryptographic seal.
Traditional electronic signature platforms — DocuSign, Adobe Sign, Dropbox Sign, PandaDoc, SignNow — prove only that an email address received a link and someone clicked it. They do not prove who signed. They do not prove the signer was physically present. They do not prove the document has not been altered since signing.
District Seal captures a cryptographic evidence record at the moment of signing. That record is what a court, an auditor, or a counterparty would need to resolve a dispute.
The Problem District Seal Solves
Every signature is a promise. Every contract, every deed, every promissory note, every will — every one of them is an agreement that someone will do something, and the signature is the moment the promise becomes real.
When a signature is challenged in court — a forged deed, a repudiated contract, a will contested by heirs, a borrower who denies signing a promissory note — the paper trail usually comes down to an email log and an IP address. That log does not prove who signed. It proves that someone clicked a link.
District Seal closes that gap.
What a District Seal Certificate Contains
Face match — the signer's identity is verified against a reference photograph using ArcFace-grade facial recognition
Randomized spoken challenge phrase — three words generated per transaction, spoken aloud on camera. A pre-recorded video cannot be replayed because the phrase did not exist until the moment of signing.
Presence check (head-turn) — the signer turns their head on cue, defeating static photographs, printed masks, and screen replays
Hardware-backed device authentication — WebAuthn / FIDO2 confirms the signer's physical device is present at the moment of signing
SHA-256 cryptographic document seal — the certificate is cryptographically bound to the exact document. Change one character and the entire seal breaks.
Public verification URL and QR code — a court, an auditor, or a counterparty can independently verify the record without an account, without an appointment, and without a phone call to us
Full forensic timeline of every step in the signing ceremony, timestamped in UTC
Signer forensics — IP address, user agent, and (when supplied) device fingerprint, all sealed into the certificate
How the Signing Ceremony Works
The document originator uploads a PDF contract and a reference photograph of the signer
The system generates a randomized spoken challenge phrase and sends the signer a signing link
The signer opens the link on their own device and completes six verification steps:
WebAuthn hardware-backed device authentication
Forced document scroll to 100% (the signer sees every page before signing)
Informed consent — recorded and timestamped
Spoken challenge phrase — the signer reads the randomized three words aloud on camera
Presence check — the signer turns their head left, then right, on cue
Face match — the signer's face is compared against the reference photograph
Every step is timestamped and sealed into a forensic event log
The signed document is hashed with SHA-256 and bound to the certificate
The certificate is delivered to the signer and the document originator
Anyone can verify the certificate at any time by scanning the QR code or visiting the public verification URL
Privacy and Data Handling
Privacy is architectural, not marketing. Voice and video are processed on the signer's own device and never reach NEXSIM's servers. The company retains only the cryptographic hash, the forensic timeline, and the reference photograph, which is destroyed automatically after 30 days.
Zero biometric media retention — no voice recordings, no video captures stored
GDPR compliant — European Union data protection standards
CCPA compliant — California Consumer Privacy Act
US-hosted — all data stored in the United States
Reference photo retention — 30 days, then automatically destroyed
Certificate retention — 7 years per U.S. record-keeping standards for signed instruments
How District Seal Is Used
Dashboard — sign up, upload a PDF contract and a reference photograph, send the signer a signing link, and receive a court-admissible certificate when they complete the ceremony
REST API and signed webhooks — for platforms and engineering teams that need identity-verified signing embedded in their own application. Full API documentation is available at districtseal.com/docs.
Who Uses District Seal
Title companies and escrow officers — wire fraud, forged deeds, repudiated closings
Law firms — engagement letters, settlement agreements, dispute-prone contracts
Platforms and developers — via REST API and signed webhooks
Notaries
District Seal does not replace notaries. When a state statute requires a commissioned notary, District Seal customers still use one. District Seal adds a cryptographic evidence layer underneath the signature, so the notarial act is protected by irrefutable proof.
Pricing
Free — 1 signature, no card required
Pay-as-you-go — $25 one-time for 10 credits (never expire)
Pro — $29 per month, 25 signatures per month
Firm — $99 per month, 150 signatures per month
API Starter — $250 per month, 200 identity ceremonies, full REST API access
API Scale — $750 per month, 1,000 ceremonies, higher rate limits
Enterprise — custom pricing
Unlimited team seats on every plan. No per-user pricing.
About the Founder
Etonde Fael Synclair — Founder and CEO of NEXSIM LLC.
Synclair is a self-taught software developer based between Cameroon and the United States. He built District Seal end to end — including the biometric verification pipeline, the certificate generator, the cryptographic document sealing system, the REST API, and the billing infrastructure — after witnessing a signature dispute that could not be resolved in court because the existing electronic signature record was insufficient.
He is the author of the technical architecture behind District Seal and remains the sole engineer and operator of the platform.