What is Trust Store on iPhone?

In simple terms, The Trust Store contains the digital signatures of issuers of the SSL certificates that are used to encrypt access to websites and email servers. There are billions of SSL certificates in use around the world. They are issued by a relatively small number of agencies and companies (Called Certificate Authorities, or CAs), who, as part of the process of issuing the certificate, verifies that the site is legitimate. When you visit a website the certificate from that site is sent to your browser. Your browser then verifies that the certificate was issued by one of the agencies whose signature is in the Trust Store. If the signature is not in the trust store you see a warning that the site may not be what it seems. The Trust Store is updated as part of an iOS update. It will change whenever the list of certificate authorities changes, which is very rare. The Trust Store version is actually the date and time the trust store contents were last updated. So, for example, version 2022012800 was last updated on January 28, 2022 at midnight.

The trust store version has absolutely nothing to do with security vulnerabilities. If you keep your Apple product updated to the latest version of MacOS or iOS it will be protected against all known vulnerabilities, despite whatever nonsense has been posted in the forum. 

Hey Raymond1974j,

It sounds like you're asking about a certificate that's showing on your iPhone. If so, here's a list of the current trusted certificates: List of available trusted root certificates in iOS 15.1, iPadOS 15.1, macOS 12.1, tvOS 15.1, and watchOS 8.1

If that doesn't help, check for an installed profile as they can install certificates too:

Install or remove configuration profiles on iPhone

Trust manually installed certificate profiles in iOS and iPadOS

If that's not the case, let us know more about what you're seeing. The more details you can provide the better.

Take care!