Verification Reports on Bitcoin Balance and Control
Independent verification of Bitcoin holdings for self-managed super funds.
CertainKey produces verification reports that cryptographically prove Bitcoin balance and control. Designed for SMSF trustees, auditors, and accountants who need something stronger than a screenshot.
On-chain balance verified through Sparrow Wallet and cross-checked against multiple independent sources: a local Bitcoin node, Bitaroo, and Blockstream Electrum servers.
BTC balance converted to AUD using Bitaroo's closing price at the snapshot date, providing an auditable fiat figure for EOFY reporting.
Each key holder receives a unique cryptographic challenge. Signatures are verified using Gatekeeper, proving individual control over multi-signature wallet keys.
Key participation is rated against the wallet's quorum threshold. Full participation earns an A+ rating; the report clearly states whether the quorum was met or exceeded.
You supply your wallet descriptor and a signed ownership declaration to CertainKey.
Your keys are loaded into Sparrow Wallet and the balance is cross-verified against a local Bitcoin node, Bitaroo, and Blockstream Electrum servers.
Your BTC balance is converted to AUD using Bitaroo's closing price at the snapshot date.
Each key holder receives a unique cryptographic challenge to sign with their private key, proving control over the multi-sig wallet.
All signatures are verified using Gatekeeper and key participation is rated against the required quorum threshold.
The report is drafted, reviewed with you, and finalised.
A SHA-256 hash of the PDF is stored for authentication. All sensitive wallet and key data is deleted. Your wallet descriptor hash is retained as a privacy-preserving reference only.
The final product is a verification report suitable for ATO and ASIC SMSF tax and audit compliance. Each report covers:
EOFY Bitcoin Holdings Verification
Reports are prepared in PDF format with a unique reference number for each engagement.
The cryptographic verification at the heart of CertainKey is powered by Gatekeeper, an open-source tool that runs entirely in your browser.
Browser-based Bitcoin signature verification for multisig wallets. Nothing is transmitted to a server — your keys never leave your device.
CertainKey is operated by David Pinkerton, based in Brisbane, Australia. David's background spans cybersecurity consulting (CyberCX), Bitcoin industry roles, and infrastructure engineering. He holds CompTIA Security+ and Network+ certifications.
Read the full story behind CertainKey on the blog.
If you hold Bitcoin in an SMSF and need a verification report for your auditor, or you're an accountant looking for a better process than screenshots, get in touch. Encrypted communication is supported and encouraged.
Encrypted channels available: Signal, SimpleX, or PGP. Request details via email.