If you're using FHE to encrypt a text search, then you'll generate a match/no-match boolean for each character. The server won't know which is which. Then you'd probably OR large blocks of these together, to give you a match/no-match boolean for each segment of text. Then you return all the booleans to the client, who decrypts them.
Are you saying something along the lines of - they split the data in to tokens, deterministically (no iv) encrypt each token, and then do equality comparisons on the encrypted tokens?
Maybe, and it would explain why they say you can chose a cipher and then list a bunch of standard symmetric ciphers. However such schemes usually leak too much in practise (even at the granuality of whole words).
More importantly, it really doesn't matter. They have both the key and the encrypted data. If someone hacks their system, the best encryption in the world won't help if the attacker steals both.
> Vaultree's proprietary encryption breakthroughs are in various encryption technologies traditionally limited to niche use cases. We finally enable users to process entirely encrypted data with Fully Homomorphic and Searchable Encryption (FHSE) and other technologies in the field. Explaining what they are would take all day, but here's a one-liner: FHSE enables data processing to be run directly on encrypted data in the same way as on plain text data.