[sandworm101]

What is the computational burden of FHE over doing the same operation in plaintext? I realize that many cloud proponants think that FHE may allow them to work with data without security worries (if it is all encrypted, and we dont have the keys, it aint our problem) but if FHE requires a 100x or 1000x increase in processor capacity then i am not sure it will be practical at scale.

[layer8]

It’s at least a million times slower than non-encrypted computation. 1000x or 100x would be a huge progress.

[sandworm101]

Oh. It really is that bad still. So if the question is between wrapping the plaintext in layers of security, or building out a million new server instances to do it via FHE, i know which one everyone will choose.

[bgnn]

It's so bad that the only way FHE can get more efficient is to use a non-conventional compute technology. Some want to do it in optical donain.

[j2kun]

It is not that bad these days, closer to 10,000x.

Accelerators are being developed that claim to get down to 10x, though i think they will be more like 100-1000x, which would still be a huge improvement considering how people use LLMs today for basic tasks like string matching.

[aitchnyu]

Are those accelerators software-only? 10x could let 4$ VPS run server side checks for backup software (evil clients cant clean backups) and git forges (eg, dont allow X to push to main).

[vishakh82]

It's really not that bad. We're close to using FHE in a production consumer app.

https://vishakh.blog/2025/08/06/lessons-from-using-fhe-to-bu...

[adgjlsfhk1]

if you're talking about doing database queries on a 5mb database, why not just ship the database client side and have them do the computation?

[vishakh82]

You may wish to build a protocol where third parties can asynchronously operate on user data. You may also want to have separation between the end app and the compute layer for legal or practical purposes. Finally, you may not want to store large payloads on client devices.

[adgjlsfhk1]

5mb is hardly a "large payload"

[vishakh82]

I'm giving you general reasons why this is the case. For our own app, we hope to build a protocol where third parties can operate async on user data (with consent).