The traditional way that nerds verify that the files they get are the same files that everyone else is getting, is with file hashes or checksums.

For every file that is provided, the person who provided it also makes available a hash for that file. But the hash should be made available from a separate place than the file that it is associated with, or anyone who substitutes the file for malware can just replace the matching hash.

In the real world, most people are too lazy to check these. But you should learn to do it for your own sake, until ElectrumSV can download and validate updates for you.

You can get the hashes for the files we make available to download, from the official ElectrumSV git repository.