Public-key cryptography, and RSA in particular, is increasingly important to e-commerce transactions. Many digital consumer appliances (e.g. set-top boxes and smart cards) are now expected to send and receive RSA-encoded messages. Decoding these messages is processing intensive and the ability to do it efficiently offers enormous value. This paper describes how MIPS Technologies achieved a 4x speedup on the RSA algorithm—without modifying the processor hardware.