Checksums 101: How to make sure your downloads are the real deal
(iMore iPhone)

One simple step can help keep your computer free from malware. Cybercriminals never rest, always seeking sneaky new ways to wreck your computer for fun and profit. And while the App Store — knock on wood — seems to have built a wall high enough to keep them out, Mac apps sold outside its gates aren`t so lucky. Even trusted apps can unwittingly become Trojan horses for various bad actors. Luckily, you can authenticate these apps before you ever install them by learning how to validate their checksums. Vali-what their check-huhs? To create a checksum, you run a computer file through a cryptographic algorithm – a series of calculations designed to turn that file into a sequence of letters and numbers. It only works in one direction; you can`t run a checksum back through another algorithm and wind up with the original file. But the algorithm is set up so that even tiny changes in the original file lead to big differences in the resulting checksum. If you run that al...