摘要: Mobile code technology has become a driving force for recent advances in distributed systems. The concept of the mobility executable raises major security problems. In this paper, we deal with protection mobile from possibly malicious hosts. We conceptualize specific cryptographic problems posed by code, and are able to provide solution some these present techniques achieve "non-interactive evaluation encrypted functions" certain cases give complete problem important instances. further way which an agent might securely perform primitive-digital signing-in untrusted execution environment. Our results based on use homomorphic encryption schemes function composition techniques.