Cryptographic Trust Infrastructure

SigBond

The first platform where both sides of every transaction build a verifiable, portable reputation. Cryptographically signed. Impossible to fake.

See the Interactive Demo → How it works
0
Platforms that review both sides
4.5M
Fake reviews removed by Trustpilot (2024)
$210M
Trustpilot revenue on one-sided reviews
The Problem

Digital trust is broken

Every review platform today is one-directional, centrally controlled, and trivially gamed.

One-sided reviews

Buyers review sellers. Nobody reviews buyers. Contractors can't check if a client pays on time, communicates clearly, or has a history of disputes.

Fake & manipulated ratings

Reviews are text in a database. Platforms write them, delete them, curate them. There is no mathematical proof that any review is authentic.

Platform-locked reputation

Your 5-star rating on one platform means nothing on another. Reputation is siloed, non-portable, and owned by the platform — not by you.

No transaction proof

Anyone can leave a review. No existing platform requires proof that a real transaction occurred between reviewer and reviewee.

How It Works

Two-way cryptographic trust

Both parties sign. Both parties review. Neither can deny it. Nobody can alter it.

01

Sign up & get your keypair

Normal signup by email. Behind the scenes, SigBond generates a cryptographic keypair on the Nostr protocol. Your public key is your identity. You never see the cryptography.

02

Both parties co-sign

At the point of agreement, both parties confirm the transaction on SigBond. This dual cryptographic attestation proves a real transaction occurred between two identified parties.

03

Independent reviews

Both parties write their reviews independently. Reviews are held in escrow — neither can see the other's until both commit. No retaliation bias. Honest by design.

04

Cryptographic publication

Reviews publish as signed Nostr events with mathematical proof of authorship, timestamp, and transaction link. Permanent, distributed, tamper-proof.

05

Payment verification

Users pay in pounds by card. The backend converts to a Lightning Network micropayment via Strike API, producing a cryptographic receipt as additional proof. No crypto knowledge needed.

06

Portable trust score

Each verified transaction builds a trust score — for businesses and individuals. Embed it, share it, or let third parties query it via API. Your reputation follows you.

Why SigBond

What makes this different

Not better reviews — provable ones.

Architecture

Two-way by design

Not an add-on. The entire system is built around mutual review. Both parties must participate. Both build reputation. The asymmetry ends here.

Cryptography

Mathematically provable

Every review is a signed Nostr event. Public key proves authorship. Timestamp proves when. Transaction link proves it happened. No trust required in the platform itself.

Anti-fraud

Fake reviews are structurally impossible

Fabricating a SigBond review requires two independent cryptographic identities co-signing a transaction. Trustpilot removed 4.5M fakes in 2024. SigBond makes them architecturally impossible.

Portability

Your reputation, forever

Your Nostr keypair works on any compatible service. Your reputation isn't locked to SigBond. If we disappear, your trust score survives on distributed relays.

See the mechanism in action

Walk through the complete SigBond flow — from keypair generation to cryptographic publication. Real cryptography, working in your browser.

Launch Interactive Demo →