On a ARM72 Cryptography Unit is optional:
https://developer.arm.com/ip-products/p ... cortex-a72
I was disappointed because I looked up the specs when the RPI4 was introduced. Optional, checked: the RPI4 doesn't have it.
IMHO encryption is used everywhere and always nowadays in every form of communication: HTTPS, rsync, ssh, backups etc. Thus I would say important.
Probably more useful then MPEG2 HW-decoding, or even H264 HW-encoding: speed is nice, quality sucks.
That 1 dollar remark was made because I'm curious about the extra costs for hardware crypto extension enabled/added.
I wonder if the extensions were skipped on the RPI4 because it was to expensive (production / patents), to complicated (hardware/software), or simply because there is no practical perceptible gain to expect.
Speed is not all, I mostly worry about my RPI4 running hot (especially in summer), and interference.