Is it possible, for example using a preshared key (password) instead of using public key algorithms in syncthing, or adding wireguard on top of it, but that probably wouldnt wort seamlessly on android.
Or any syncthing alternatives that dont use quantum vulnerable algorithms?
The threat is spying and storing data of the ISP (less likely) and for sending data to the untrusted node that act as a server so the sync always works