Description:This book constitutes the thoroughly refereed post-conference proceedings of the Third Symposium on Trustworthy Global Computing, TGC 2007; it moreover contains tutorials from the adjacent Workshop on the Interplay of Programming Languages and Cryptography, both held in Sophia-Antipolis, France, in November 2007.The 19 revised papers presented together with 3 invited papers were carefully selected from 48 submissions during two rounds of reviewing and improvement. The TGC 2007 symposium papers focus on providing tools and frameworks for constructing well-behaved applications and for reasoning about their behavior and properties in models of computation that incorporate code and data mobility over distributed networks with highly dynamic topologies and heterogeneous devices. The volume concludes with 3 tutorial papers, presented at the co-located Workshop on the Interplay of Programming Languages and Cryptography.