Even without bootstrapping FHE will never be as fast as plaintext computation: the ciphertext is about three orders of magnitude much larger than the plaintext data it encrypts, which means you have to have more memory bandwidth and more compute. You can’t bridge this gap.
Technically, there are rate-1 homomorphic encryption schemes, where ‘rate’ refers to the size ratio between the plaintext and the ciphertext. They’re not super practical, so your general point stands.
That actually sounds pretty reasonable and feels almost standard at this point?
To pick one out of a dozen possible examples: I regularly read 500 word news articles from 8mb web pages with autoplaying videos, analytics beacons, and JS sludge.
That’s about 3 orders of magnitude for data and 4-5 orders of magnitude for compute.
Sure, but downloading a lot of data is not the same as compute on this data. With web you simply download the data, and pass the pointers to this data around. With FHE, you have to compute on extremely large cipher texts, using every byte of them. FHE is roughly 1000x more data to process and it takes about 1000x more time.
