Mobile application usage has increased over the years to the point where you have an app for everything. However, such a surge in mobile app downloads and development has also created a massive security challenge.
In 2020, almost every organization suffered one major cybersecurity attack due to malicious mobile download. 93% of these organizations saw malicious attacks over a device network through social engineering techniques that entice users to download unsafe payloads from URLs.
So, the question for most app developers is how to ensure application security?
The answer to all these security questions is a code-signing certificate. It is a process of assigning a certificate to an application by a trusted certification authority or CA. So, when a user downloads and installs the application, validation of the trusted publisher becomes easy.
CA will issue certificates after vetting of the application publisher and encrypt the information through a public key. Further, users can leverage public keys from app developers to determine the identity of app publishers. Though it may seem a simple step towards app security, you need to factor in several aspects.
So, here we are with a comprehensive take on the code-signing certificate and some best practices to follow for your business. First, let’s start by understanding how it works.
What is a Code-signing certificate?
When a software developer or app publisher signs their products with a digital signature, they encrypt the executable file, distribute it to users for installation. The digital signature serves as a security sign for users who believe it to be the authentic software or app to install.
The digital signature also ensures that the software or app is not tampered with and safe for users to install on their devices. Every digital certificate, whether its SSL or code-signing certificate, works on PKI or Public Key Infrastructure.
The entire process begins with generating a unique security key that is used to encrypt the information or data. Then, a public-private key pair mechanism is used for the encryption and decryption of any data. When a developer generates such a key pair, the public key is sent to a CA or Certificate Authority to verify the developer’s details.
After proper vetting of developer credentials, CA attaches a public key with the digitally signed certificate, which acts as a proof for the developer’s ownership of the key. However, developers need to hash the software or app’s code before code-signing or affixing a key pair to the software.
Hashing is converting data files into an array of string values that is hard for hackers to break. In addition, a hash function can alter the application software code into arbitrary values, further encrypted through a private key.
Developers can create a signature block or a combined code from the merger of hashed value digest, code-signing certificate, and hash function. It becomes easy to insert a signature block into the software and make it secure for distribution.
Now that you know how a code signing works, let’s discuss some of the best practices and factors to consider when buying a code signing certificate.
Best Practices for Code-signing Certificate
Knowing the technology and using it are two different things. The same goes for code-signing certificates, where execution is essential to ensure enhanced security. So let’s discuss some of the best practices to follow when using a digital signature for your applications and software.
Security over functionality
The dilemma of functionality vs. security is massive for several businesses. As a result, many organizations even compromise on the security aspect to enhance the functionality of their application software.
However, this can impact their operations as data leakage, and malicious attacks can reduce your software and trust among customers. So, it is essential to leverage code signing practices along with the functionality aspect of apps.
How can you achieve both security and functionality?
Here, the best practice is to buy a code-signing certificate from a vendor that offers enhanced encryptions without compromising the functionality of an application. You can also leverage the MVP model or Minimum Viable Product with a test-signing certificate, apart from the vendor-specific features.
Minimum Viable Product or MVP is a shippable product that you can create for your application with minimal features. So, you need to understand the difference between test-signing certificates and release-signing certificates.
A test-signing certificate specifically assigned for MVPs or test environments is different from the final code signing certificate used in the product to be released. Test-signing certificates need various root certificates than the ones to be used for publicly released software.
This enables you to ensure that test-signing certificates do not end up risking your software’s security. Most test-signing certificates leverage internal CAs to issue the certificate, which is not as trustworthy as those offering release-signing certificates.
As test-signing certificates are specifically designed for test environments, you need a more reliable solution for the production-grade version. However, minimizing the access to the initial private key generated for certification can be an excellent way to ensure security apart from the different root certificates for test-signed and release-signed certification.
Limiting key access
While you generate private keys for the code-signing process, keeping the access restricted makes more sense. The best way to ensure that your private keys are protected from exposure to malicious cyber attacks is to have physical access for specific people within the organization.
Another essential aspect is to have private keys stored securely to avoid the risk of a data breach. You can leverage cryptographic hardware certified by FIPS 140 Lever-2 or better to protect the private keys.
FIPS or Federal Information Processing Standard is a validating standard that authenticates whether cryptographic hardware is validated and tested by the US Government. Apart from this, you can also use time-stamping of codes to ensure better verification after the certificates get expired.
Time-stamping your code can help you authenticate your certificates to be in operation while it was digitally signed. In layman terms, a hash of your code is uploaded on the server to record the time and date of receiving the time stamp certificate. So, when your certificate expires, there is a record that helps vet the application or software publisher.
Timestamping is done through TSA or Time-stamping Authority which works independently from the code-signing system(CSS). While CSS relies on CA for validation, the TSA synchronizes the records for a verifying entity to authenticate the time stamp of the app publisher even if the expiry of the private key is revoked or in effect during the code-signing process.
With the rising popularity of applications and software, the need for enhanced security measures is increasing. Using code signing practices can be the best option for your software products. However, you need to assess specific requirements before you buy a code signing certificate.
For example, you need to assess requirements of central data management, auditing, control of security leys, and even extra features like malware scanning before you decide to buy a code signing certificate.