Verification Sample App of Open Attestation-based Vaccination Certificate

Ong Khai Wei
1 min readOct 31, 2021

Recently I got involved into discussion about international traveler and one of the important element is vaccination certification. Singapore government is innovative and leveraging blockchain technology to verify the authenticity of the vaccination certification.

Open Attestation

Open Attestation is an open-sourced framework to endorse and verify documents using the blockchain. GovTech is main contributor for this framework (seem like enhancement of OpenCert) and vaccination certification is leveraged on Open Attestation standard.

Not an expert on Open Attestation, I am still exploring Open Attestation, more information is available at:

Sample Web Application

The official documentation is based on command-line interface. It wont be so convenient to verify the each of the .oacertificates using Terminal. After studying some of documentation in github (, I develop a simple web application to upload vaccination certificate in the form of .oa and to verify the certificate.

Open Attestation Verification Application

This is just the first step to explore the 2 of the functions wrappedDocument and verifySignature . The sample code is available at my github