This proposal aims at the development of a new secure computer model called the Garbled Computer (GC). An adversary observing the computations of a GC learns nothing about what it is doing, what data it is operating on (whether inputs or intermediate values), and the outputs it is producing. The GC achieves, using a single general approach, the multiple goals of software obfuscation, tamper-proofing, data confidentiality and data integrity. The GC enables execution, on untrusted platforms, of trusted and confidential code whose inputs and outputs are sensitive. For example it can enable the utilization of Amazon cloud services without revealing to Amazon the nature of the computation or the data, and without requiring Amazon to change the operation of its cloud services (i.e., use standard off-the-shelf services).