>Honest question: Can't I do that already by using SFTP or ssh and uploading a spreadsheet? I just feel like I'm missing something. Do you have some kind of rea

>Honest question: Can't I do that already by using SFTP or ssh and uploading a spreadsheet? I just feel like I'm missing something. Do you have some kind of real-time aspect going on? No, you aren't encrypting the computation, just encrypting some data. Using secure computation (garbled circuits, secret sharing, homomorphic encryption, ...), you are encrypting every mathematical operation. > Second question: How do I know that your closed-source app isn't exfiltrating the data clandestinely? >Assuming no flaws are ever going to be discovered in your crypto scheme in the future is pretty bold. What I've written is: if you are carrying the secure computation on your private LAN and nobody is sniffing the traffic (potentially gigabytes), in the future they will have no way to cryptanalyze what the inputs were. And you can check that no information is being sent to anywhere during the secure computations: all the encrypted data is sent between the two computers carrying out the secure computation. > Given that anything orbiting the earth can be observed from the ground with sufficient resolution, there's no such thing as a secret orbit. This sounds more and more like snake oil. You can learn more here: https://eprint.iacr.org/2013/850 https://eprint.iacr.org/2013/850 https://eprint.iacr.org/2016/319 https://eprint.iacr.org/2016/319