...or otherwise invalid certificates from *being used*. from use reads ok to me - maybe it's not recognized as standard in the UK?
...OCSP services must be discoverable, fault tolerant and *have* low latency.
don't care, but why not "have fault tolerance" too?
3. Practical Considerations and Expectations ...presents a *scalability* problem...
3.1 Certificate Revocation Lists ...somewhat like *a trusted* responder)... No, this changes the sense, what was meant should perhaps have been
7.1.2 OCSP Clearing house In order for such a service to be *trustworthy*...
Ok, but scalability seems to me like a concept applied to a particular service and scaling applied to a problem or a system as a whole. So we need a scalable solution to a scaling problem. Maybe that's idiosyncratic usage, sorry if so. put in quotes then, like a "Trusted Responder (see below)" trustable or trusted reads better to me; "trustworthy by" doesn't seem right.
9 Other Considerations (I feel the first sentence is rather clunky - perhaps something like the following is better) While OCSP as a technology has been around for several years, *it has yet to make a significant impact to the Grid community.*
This sentence implies the wrong relationship between OCSP & Grids. It suggests that there is something wrong w/ OCSP that has kept it "from use" in Grids. That may be, but is yet to be shown. The existing sentence may be phrased better somehow ("if used are not..." is better verb agreement) but reflects the sense of the relationship between Grids & OCSP better.