This paper presents a new approach for diagnosing stuck-at and short faults in interconnects whose layouts are known. This structural approach exploits dierent graph coloring and coding techniques to generate a test set with no aliasing and confounding. The conditions for aliasing and confounding are analyzed with respect to the size and number of the shorts in the fault set. The characteristics of unbalanced/balanced codes for encoding the colors in the vector generation process for interconnect diagnosis are discussed and proved using a novel algebra. An algorithm for diagnosis is then presented.