Those certainly exist and are used frequently in systems that require very high performance encryption, but what DJB is trying to do is ubiquitize encryption ca

Those certainly exist and are used frequently in systems that require very high performance encryption, but what DJB is trying to do is ubiquitize encryption capability. A massive first step was taken when AES instructions were added to Intel CPUs, but more could be done. The advantage of having it be ubiquitous in the CPU is overall cost is reduced and the ability to utilize encryption in more and more places is increased since users aren't stuck waiting.