Problem 5: Public key infrastructure doesn’t exist
In theory, public key eliminates the need for pre-agreement
- public data establishes that endpoints hold corresponding secret
- but how do we know a published public key is the “real” one?
One answer: certificates
- bind a public key to the name of its “owner”, signed by an “authority” with a well-known key
Certificates help establish keyholder identity, if the right data are certified & the authority is trusted by the recipient
Unfortunately, this requires a certification infrastructure
- none exists yet, and current proposals aren’t very promising