reuse signed jars

[persal]

Signing jars takes a lot of resources, so is there a way to not having to do this over and over (when performing mvn clean install)?
Having all jars signed before adding them to our artifactory might be one solution (or paying for enterprise edition?).

I'm thinking on having a cache with signed jars and a hash for the unsigned jar to find it, and then instead of signing, check the cache using a hash to see if there already is a signed version of the jar i'm about to sign. If there is no signed jar, sign it and cache it for the next time.
Is there a hook into the webstart-maven-plugin plugin where I can try to add this perhaps?
Perhaps easier to extend the actual plugin itself?

Any other creative ideas?

[persal]

I see that there is a "DefaultSignTool" for the interface/component "SignTool" using @component( role = SignTool.class, hint = "default" )

Is it possible by maven configuration to use another custom SignTool implementation?