Code Signing Certificates: Like An SSL For Executable Files?

Kind of, but not really. Let’s talk about the similarities and differences between code signing and SSL certificates.

Code Signing Certificates share some similarities with SSL certificates, but share many more differences. While both use Public Key Encryption to help secure things, the similarities more or less end there. Code Signing is for programs – scripts and executables – SSL is for websites. But let’s look at the similarities and differences a little more so you can keep your digital certificates straight.

What are the similarities between Code Signing and SSL?

There are a few similarities that both types of digital certificates share, here are a few:

• Both are Digital Certificates
• Both must be issued by trusted Certificate Authorities
• Both require users to complete a Certificate Signing Request
• Both require some degree of validation before issuance
• Both make use of Public Key Encryption
• Both use Private keys

That’s where the similarities end, though.

Code Signing is for Programs

When you make use of a Code Signing certificate you’re using it to help secure software. Well, maybe secure is a bit of a misnomer. Code Signing doesn’t encrypt the program itself, so it’s still possible to alter it. But like the dye-packs that banks use, the second that someone tries to alter the software they trigger and give immediate notification that something is amiss. In Code Signing’s case, this is done via hashing. Any alteration to the program alters the hash value that the program and its signature block are supposed to produce when hashed together.

So it’s really more accurate to say that Code Signing provides assurance. It provides assurance that program hasn’t been altered or tampered with, and using the digital signature is can verify the identity of the developer. Without Code Signing, browsers wouldn’t be able to verify identity and would instead warn users that they’re about to download something from an unknown source. So Code Signing is essential for keeping your software trusted and assuring users that it comes as intended.

SSL/TLS is for websites

By contrast, SSL/TLS is a protocol for encrypting the communication that occurs between a website and its visitors. When communication is encrypted it’s called a Secure connection. One are that SSL is like Code Signing is that higher-end certificates can provide assurance of identity. Both Organization and Extended Validation certificates provide verified business details when viewing the certificate. EV even showcases the organization’s name beside the URL in the address bar.

When a website installs an SSL certificate, it can migrate its URLs to HTTPS using 301 redirects and make secure connections with its users. Encrypting communication prevents third parties from intercepting the traffic and either impersonating the user or injecting content.

SSL/TLS and Code Signing are not interchangeable

Your SSL certificate can’t sign code for you and your code signing certificate won’t encrypt your website’s connections. They are two distinct products with distinct purposes. Both are necessary, but neither does both.