Secure multiparty computation (MPC) is a powerful cryptographic technique which allows mutually distrusting parties to compute a function on their shared inputs. MPC can be viewed as encompassing two main categories, secure function evaluation (SFE) where the function being computed is known to all parties, but the input data is private, and private function evaluation (PFE) where one party has a private function while the other party has private data as input to the function. A major reason MPC has not seen more widespread adoption is due to the fact that to create an efficient MPC protocol for a specific function, traditionally expert cryptographers have had to hand build a custom protocol. One attempt to remedy this issue is the creation of MPC compilers which take as input code in a high-level language and output an optimized MPC protocol. Another attempt has been garbled processors which are hand optimized MPC protocols which emulate specific computer architectures. This thesis presents MPC SUBLEQ, a garbled processor designed for the PFE setting. In particular, it emulates the subtract-and-branch-if-less-than-or-equal-to-zero (SUBLEQ) one-instruction set computer (OISC). Because SUBLEQ only has a single instruction, there is no overhead cost to hide what instruction is currently being executed as there is only one instruction to execute. The data which the instruction is executing on must remain private, but the instruction itself is always known. We also test and compare MPC SUBLEQ against GC-Lite, a similar garbled processor designed for PFE using the SUBBLE OISC, a weaker version of SUBLEQ. We show that MPC SUBLEQ dramatically outperforms GC-Lite due to the significantly lower local computation and online communication costs.