This is reminiscent of a recent idea of mine. Imagine the following signed declaration: I (fingerprint = ...) claim that the code X with SH (secure hash) = ... satisfies contract with SH= ... when its free code pointers are bound to other code conforming to contracts identified within X by their SH's. The contracts would be either formal or informal. When a Java program arrives at a client it can warrant its services if it finds local access to warranted sub-routines. (For this purpose behaviors of objects are sub-routines.) The Java loader can build warrants recursively with such declarations. They would, of course, be relative to the reputation of signers of the above declarations. I have just sent for your paper.