The benefits of distributed computation present complex security considerations beyond those associated with the traditional computing paradigm. This paper describes a bandwidth efficient approach to authenticate distributed Java code. Our system utilizes steganographic techniques to embed a cryptographic checksum as a tamper detection mark into Java class files. The properties of this mark make our system desirable in applications where low bandwidth utilization is a requirement (e.g., wireless networks and low power devices). We have implemented our system in Java and evaluated its performance through empirical study. Analysis indicates that our system detects any degree of alteration to a marked Java class file and can do so within a reasonable amount of time.