In this consultation response Open Identity Exchange highlights 3 key delivery challenges for Covid Certificates: 

• User Trust and Certificate Issue
• Certificate Collation and Status Determination 
• Certificate Interoperability

The conclusions drawn by the paper are that UK Government, and the NHS, should consider the following:

• Issue citizens with digital covid vaccine certificates through existing technology: Patient Apps.
• Deliver data within the certificates in a recognised international standard format. International standards are still emerging – UK Government be part of their definition.
• Select a certificate protocol that will be internationally accepted and will work offline.
• Prepare to be an “Issuer” in a trust framework that allows the organisations to consume covid certificates or information derived from then. Be part of the chain of trust.
• Work with the identity industry, either directly or through OIX, to:
• Determine use cases where covid certificates will be required.
• Determine the rules for each use case. Or at least provide guidance. Private sector is calling for government guidance on this – abdicating responsibility to the private sector is going to result in slow take up and inconsistent citizen experiences.
• Ensure users can get their covid certificates into their digital wallets or associated with a digital identity.
• Consider whether a specific trust framework is needed for use of covid certificates in the UK, for example entrance to venues or use in employment. Should the UK government put in place rules for the use of covid certificates and a trust framework to govern these rules?
• Whilst this document focusses on digital covid certificate delivery, machine readable paper based versions of certificates should also be able to be issued. These should be able to be digitised into a user’s digital wallet or digital identity if the user wishes, to allow them to be easily presented to organisations.

The full repoonse call be reviewed here: https://openidentityexchange.org/networks/87/item.html?id=447