Code Signing with Digital Certificates: Explained (2023)

Code Signing with Digital Certificates: Explained (1)

Imagine you’re installing an application and a pop-up like the screenshot above comes up. How can you be sure that the application you’re about to download is really safe?

The answer is code signing certificates, which attest that the software package has not been tampered with or replaced with a modified version. It’s a virtual tamper-proof seal that verifies the code is the authentic original version, preventing scenarios where a bad actor might upload an infected version of a common application.

In addition to protecting users from accidentally downloading viruses, code signing certificates prevent security warnings, like the one above, from stifling the user experience. SecureW2 offers a turnkey PKI solution with #1 rated certificate delivery so you can take advantage of code signing certificates. Learn from one of our customers how easy our PKI solution is to configure.

In this article, we’ll take a closer look at code signing certificates and explain how they work and why they are so important.

Understanding a Code Signing Certificate

Code signing is done by putting a digital signature on an executable, software update, or file. The certificate confirms that the program has not been tempered and the software is safe for download.

You can think of it as a wax seal on an envelope. If the seal is intact, you can be certain that the letter hasn’t been modified with or replaced by an outside source. Apple developers use code signing to prove, for instance, that your macOS update actually came from Apple, and not a hacker who is trying to compromise your computer.

All major operating systems and browsers and OSs support code-signing software.

How Does Code Signing Work?

In order to understand code signing, first, you need to understand what a PKI is.

The purpose of a Public Key Infrastructure (PKI) is to create and manage public-private key pairs (in the form of X.509 digital certificates) used by the network for identity management and access control.

A PKI allows users and systems to verify the legitimacy of certificate-holding entities and securely exchange information between them over the air. The introduction of a PKI enables the use of code signing certificates through public-key encryption.

The process for code signing is as follows:

  1. A developer uses a PKI (like SecureW2) to add a digital signature to a code signing certificate.
  2. A user has a public key that is used to decode the signature. The user’s software or application decodes the signature using the key.
  3. Then software searches for a root certificate with a verified identity to validate the applied signature.
  4. The software system then applies a hash to the download of the application and another hash to sign the code.
  5. If the root and hashes match, the download continues.
  6. If the root and hashes do not match, the download will be interrupted and shows a warning.

Code signing is commonly used by app developers so that users downloading an application can rest assured that it’s safe. In fact, major app distribution platforms such as Apple’s App Store and the Google Play Store require apps on their platforms to be code signed.

However, the practice isn’t just limited to app development; code signing is also utilized by IoT manufacturers and by people working on operating systems. Really, any time you have an executable, you can use the code signing process to create a tamper-evident seal for your end users.

Benefits of Code Signing Certificates

Using code signing certificates is a must if you want to maximize user experience and security. The benefits are the following :

  • Validating Code Integrity
  • Enhancing Legitimacy
  • Integration with All Major Operating Systems

Validates Code Integrity

Code signing provides an integrity check of the code by validating it with a hash function. The hash function is used at the source to sign the code and the same hash has to be matched at the destination. This provides the user with proof that the code has remained unchanged.

Enhancing Legitimacy

When users download a piece of software and are immediately issued a warning by their operating system, it can ruin the mood a little bit. Users need to be able to trust your software if you want them to continue to be your customer, and an untimely warning can damage that trust.

Code signing certificates indicate to an OS that the source is legitimate, bypassing security flags and facilitating a smooth user experience. allow your customers to trust in your software and bolster your public reputation.

Integration with All Major Operating Systems

Code signing processes are encouraged by all major platforms such as Apple iOS, Windows, Linux, Android, JAVA, Adobe AIR, etc. The partners, channels, and platforms that distribute your software expect you to safeguard their customers’ data. Signing software shows your commitment to their safety and is often a contractual requirement.

Best Practices with Code Signing Certificates

Implementing code signing certificates in your development process is a step in the right direction. However, there are additional considerations to make to enhance both your security and peace of mind, as well, such as the following:

  • Protecting your keys with an HSM (hardware security module)
  • Enforcing policies and up-to-date security practices
  • Keeping and checking auditing logs regularly

Protect your keys with an HSM.

We’ve discussed briefly what a PKI is, and the merits of having one, but it’s important to mention that PKIs are even better when they’re protected with their own security measures. The gold standard for safeguarding your PKI is a hardware security module, also known as an HSM.

In a nutshell, an HSM is a secure physical device that can operate cryptographic functions. Because they have extremely limited network access and they are themselves protected by a firewall, HSMs are tamper-resistant, highly effective guardians for PKIs.

A wise practice is to host your root Certificate Authority offline, then protect that root CA with an HSM. If this sounds more trouble than it’s worth, the good news is that SecureW2’s managed PKI already comes backed with an ultra-secure HSM.

Enforce network policies and utilize up-to-date security practices.

Your security tools are only as good as the rules you frame them with. Even if you have a high-end lock, it’s only useful as a decoration if you leave it open all the time or hand out keys to everyone indiscriminately.

In other words, build and enforce strong policies around your certificate use. One excellent practice is to support authentication within your organization with a RADIUS server. RADIUS servers basically act as bouncers on your network, checking users’ identities at the “door” when they attempt to authenticate.

Some RADIUS services, including our own Cloud RADIUS, can interface directly with your identity provider (IDP) to verify information regarding different groups of users. For example, you could use Cloud RADIUS to authenticate certificates for users on your software development team, putting them on their own VLAN or prioritizing bandwidth for them. You could even accept or deny users based on the time of day.

This may not apply directly to code signing, but it’s important to consider, anyway. Your end users can trust your organization much more when they understand that you take security seriously.

Keep and check audit logs regularly.

Event logs are critical to any network’s security. Keeping them isn’t enough, though – you also need to check them regularly.

In the event a breach does occur in your organization, a detailed event log can help you pinpoint what caused it. Checking your logs frequently in advance can also help you prevent any security issues from worsening – much like treating an illness the moment symptoms appear.

This is why our Cloud RADIUS comes with detailed event logging. When users attempt to authenticate to your network, whether they’re granted or denied access is immediately logged for your network administrators. We strongly encourage our customers to reference these logs to ensure the health of their network.

How Do I Get a Code Signing Certificate?

Code Signing with Digital Certificates: Explained (5)

There are a couple different ways you can go about acquiring a digital code signing certificate. The first method is to simply purchase the certificate directly from a reputable Certificate Authority. Unfortunately, these individual certificates can be expensive, so purchasing more than one isn’t the most economical plan.

If you want a much more scalable option, the alternative is to implement your own organizational PKI. As we’ve mentioned previously, however, building and maintaining your own PKI is a hassle. Without the proper expertise, the chances of misconfiguration are high, and hiring the expertise if you don’t already have it is costly.

This is where managed PKIs (MPKIs), like SecureW2’s JoinNow Connector PKI come into play. An MPKI takes all the frustration out of maintaining a PKI. You don’t need to build one from scratch, you eliminate the risk of misconfiguration, and the expertise required for maintenance is provided for you.

Once you’ve established a PKI, you can issue certificates as necessary without having to pay astronomical fees for each one. An important factor to keep in mind, however, is who the end-user is for the code you are signing.

The cornerstone of digital certificates and PKIs is trust. Trusting a certificate requires trusting its source first. If you use your own internal PKI to issue a code signing certificate to an app you have in the app store, the odds of a random end-user outside your organization trusting the Certificate Authority that issued your certificate are nonexistent.

Thus, using your own internal PKI to issue as many code signing certificates as you need is an excellent solution if you need to sign your code for others in your own organization. However, when it comes to creating applications that will be distributed externally, you’ll probably need to stick with using a certificate issued by a public CA that is more widely trusted outside your organization.

Do I Need a Code Signing Certificate?

While you don’t absolutely need a code signing certificate to code and release applications, being able to sign code is important to gaining the trust of your end users (and their devices!). Certificates simply present the best method for doing so.

With a certificate, the code signing process is simple. Additionally, the peace of mind end-users will gain is priceless.

Types of Code Signing Certificates

There are two types of code signing certificates — OV or standard code signing certificates and EV code signing certificates.

OV Certificates confirm the existence of the organization. To get an OV certificate, a company must complete the validation process. During validation, the certification center must ensure the legal and physical existence of the company.

EV Certificates offer the same solution as an OV certificate, but EV code signing keeps the private key secret using a hardware token whereas in regular code signing the private key is not provided in a separate external drive.

In general, both offer the same thing: signing software, scripts, drivers, or any other executable files using x.509 based certificates that are attached to a trusted root. EV certificates just have a more rigorous protocol behind them. A benefit of this is that an EV code signing certificate offers an immediate reputation with Microsoft SmartScreen, so your users will never have to click through a SmartScreen warning in Windows.

Can SSL Certificates Be Used for Code Signing?

An SSL certificate is a certificate that promotes secure, encrypted connections between servers hosting websites and the clients that visit those sites. The certificate verifies that the host server is valid, and then the end-user is able to safely connect through HTTPS.

At their core, certificates perform the same basic function: proving someone or something’s identity. Both code signing and SSL certificates do this, so does that mean they can be used interchangeably?

Unfortunately, the answer is no. Certificates are each designed for a specific use case and are encoded with attributes for that purpose. Attempting to use an SSL certificate for the code signing process will just result in an error.

What is the Difference Between a Signing and Encryption Certificate?

Code Signing with Digital Certificates: Explained (6)

Understanding the difference between encryption and signing requires an understanding of some technical information security concepts. We’ll give you a quick runthrough.

Encryption is a process related to the concept of confidentiality. When a set of data is encrypted, it is basically protected from third party observation. There are two types of encryption: symmetric and asymmetric.

Digital certificates use asymmetric encryption, which is also known as public key cryptography. We could go on about public key cryptography at length, and we have existing guides on the topic if you want more detailed information. Put simply, however, public key cryptography uses a public key that is freely distributed and a private key kept secret by the holder.

This functionality makes it possible for these certificates to be used for signatures. Just as people can encrypt messages with the public key that can be decrypted by the private key, so can the private key’s holder encrypt messages that can only be decrypted with the public key. Because the public key can decrypt the message, it’s safe to assume that it can only have come from the appropriate private key.

In other words, digital certificates function as both encryption and signing mechanisms. As we mentioned previously, however, exactly what they are being used to encrypt or authenticate varies.

Do Code Signing Certificates Expire?

Generally, certificates are only good for a certain period of time, and that includes code signing certificates. A certificate wouldn’t be the best authentication method if it was valid indefinitely – just like using the same password forever isn’t exactly secure.

The exact lifespan of your code signing certificate will vary depending on how you acquired it. Different certificate authorities offer various life cycles for their certificates. These certificates tend to be valid for a couple of years.

The problem is that applications are often used for more than a couple of years. You can code-sign an application with a certificate that expires after two years, but people may still be downloading your application several years later. How do those people know that your code hasn’t been tampered with since the expiration of the certificate?

The answer to that question is timestamp counter signatures. If you’ve gotten your code-signing certificate from a public CA, you can also request a signed timestamp that includes the current date and time from that CA. In the future, when the end-user checks the signature, they can see the original certificate and the time stamp that confirms that the certificate was “in date” when the timestamp was administered.

If you’re using our JoinNow Connector PKI to generate code signing certificates, you’ll have the ability to choose the length of time the certificate is valid for. You can even designate a particular date for expiration if you choose. Remember, however, that as far as code-signing is concerned, this setup works only for internal use, where you can ensure that employees and devices in your organization trust your own CA.

Code Signing Certificates With SecureW2

Code signing certificates, as well as certificates for other use cases, are an essential part of software development and a way to prove your commitment to security to end-users, but making sure you have the proper tools to utilize them internally is paramount to success.

In the past, IT professionals have chosen to avoid implementing certificates because the thought of managing a PKI was too big a hassle. With SecureW2’s PKI solution, you get everything you need to secure your network, without any of the usual headaches like massive infrastructure changes or lengthy deployments.

Besides being vendor-neutral and able to integrate with your existing infrastructure, using our managed PKI service can save you the expenses involved with building your own PKI from scratch. We provide you the PKI with no need for costly on-prem infrastructure or the need to hire additional personnel with PKI experience. Take a look at our pricing yourself and see just how affordable our secure managed PKI can be.



What is a code signing digital certificate? ›

Code Signing Certificates are used by software developers to digitally sign applications, drivers, executables and software programs as a way for end-users to verify that the code they receive has not been altered or compromised by a third party.

What is the difference between code signing and digital certificates? ›

Code signing certificate is used for securing software while SSL certificate is used for securing internet communication. But the issuing authority of certificates can be same for both kinds. In both the cases, a pair of public and private keys are used to encrypt or hash the software or the communication path.

What is digital signature for code signing? ›

Code signing is the process of applying a digital signature to a software binary or file. This digital signature validates the identity of the software author or publisher and verifies that the file has not been altered or tampered with since it was signed.

What is digital signature and digital certificate explain briefly? ›

A digital signature is an electronic type of signature used to authenticate a digital document. A digital signature certificate holds the public key and personal information of the signer. Digital Signature Certificate binds the public key to a certain individual or organization.

What is an example of a code signed certificate? ›

Examples of mobile certificates are Windows Phone, Windows Phone Private Enterprise, Java Verified, Android, and Brew. Some examples of code-signed software are Windows applications, Windows software updates, Apple software, Microsoft Office VBA objects and macros, .

How does a signing certificate work? ›

A publisher or developer signs a file using the code signing certificate. A digital signature is attached to the file and a hash mark is created. The content is published to a web site or mobile network, or otherwise made available. A user downloads or encounters the code.

What is required for code signing certificate? ›

To get an IV Code Signing certificate there are three different requirements: Identity Verification. Telephone Verification. Final Verification Call.

Which is better digital signature or digital certificate? ›

The most basic difference between a digital signature and a digital certificate is that a digital signature is used to verify the authenticity of a specific document, whereas a digital certificate is used to create an identity for a website.

Is a digital certificate a private key? ›

A digital certificate, also known as a public key certificate, is used to cryptographically link ownership of a public key with the entity that owns it. Digital certificates are for sharing public keys to be used for encryption and authentication.

What is the purpose of a digital certificate? ›

Digital certificates facilitate secure electronic communication and data exchange between people, systems, and devices online. They are issued by Certificate Authorities (CAs) and perform two primary functions: Verifying the identity of the sender/receiver of an electronic message.

How do you do digital signing? ›

Acrobat Sign automatically sends you and the sender the final signed document.
  1. Click review and sign link in email.
  2. Click prompt in document.
  3. Create electronic signature.
  4. Select signature option.
  5. Sign document.
  6. Finalize signature.
  7. Send.

What are the benefits of code signing? ›

Helps authenticate the identity of the developer, promoting trust on both sides of the transaction. Provides proof that the software has not been tampered or meddled with, and is being consumed in the way it was meant to be consumed.

What is in a digital certificate for dummies? ›

It is also known as a public key certificate or identity certificate. The certificate contains the subject, which is the identity piece, as well as a digital signature. Digital certificates ensure both the identity and secure encryption of a website, individual, organization, device, user or server.

What is digital certificate in simple words? ›

A Digital Certificate is an electronic file that is tied to a cryptographic key pair and authenticates the identity of a website, individual, organization, user, device or server. It is also known as a public key certificate or identity certificate.

What is an example of a digital certificate? ›

A client certificate is a digital ID that identifies an individual user to another user or machine, or one machine to another. A common example of this is email, where a sender signs a communication digitally and its signature is verified by the recipient.

Can I create my own code signing certificate? ›

The way you can generate a self signed code signing certificate is to use OpenSSL. You have a few options as to how to go about doing this, such as using Linux or PowerShell.

How long do code signing certificates last? ›

Code Signing certificates are valid for 1 to 3 years depending on which life cycle you choose when you purchase the certificate. See: pricing information. You should also timestamp your signed code to avoid your code expiring when your certificate expires.

Where are code signing certificates stored? ›

The browser installs the certificate files in the browser's personal certificate store. Internet Explorer and Microsoft Edge install your code signing certificate in the Personal Certificate Store of your Computer Account in the MMC. See (Windows) Verifying Your Code Signing Certificate Installation.

What is standard code signing? ›

The Standard Code Signing certificate is an essential tool for application publishers, programmers and developers allowing for digital signing of code and software files. It is compatible with Java Code Signing and Microsoft Authenticode technology.

How much does a code signing cert cost? ›

CertificatesLowest Price
Sectigo EV Code Signing Certificate$266.00/yrMore Info
DigiCert EV Code Signing Certificate$524.67/yrMore Info
Comodo Code Signing Certificate$69.00/yrMore Info
Sectigo Code Signing Certificate$82.87/yrMore Info
2 more rows

How do I get a digital signing certificate? ›

Steps to apply for a Digital Signature Certificate
  1. STEP 1: Log on and select your type of entity. ...
  2. STEP 2: Fill the necessary details. ...
  3. STEP 3: Proof of identity and address. ...
  4. STEP 4: Payment for DSC. ...
  5. STEP 5: Post the documents required. ...
  6. Related Articles.
Oct 27, 2022

How do I manually create a code signing certificate? ›

Generate a Provisioning Profile manually
  1. Select Certificates, Identifiers & Profiles from the left sidebar.
  2. Navigate to Identifiers > App IDs.
  3. In the App ID Description add a recognizable name for your App ID.
  4. Select Explicit App ID and add your bundle identifier to the field.

WHO issues code signing certificates? ›

Code signing certificates are digital certificates that contain information that fully identifies an entity and are issued by a Certificate Authority such as GlobalSign. The digital certificate binds the identity of an organization to a public key that is mathematically related to a private key pair.

What is the disadvantage of digital signature certificate? ›

The primary drawback of digital signatures is that they are limited to a single digital document. Each digital signature binds to a unique online document, hash algorithm, private key, and public key.

What are three 3 benefits of having a digital signature? ›

The three main benefits of digital signature include increased contract speed, enhanced security, and lower transaction costs.

What is the most common digital certificate format? ›

PEM Format

PEM is the most common format in which Certificate Authorities (CA) issue certificates.

What are the 3 types of certificates? ›

There are three recognized categories of SSL certificate authentication types:
  • Extended Validation (EV)
  • Organization Validation (OV)
  • Domain Validation (DV)

What key is stored in a digital certificate? ›

A digital certificate contains the public key for an organization and is a statement that the public key belongs to that entity. Important: Digital certificates do not contain your private key. You must keep your private key secret.

What are the two most critical fields in the digital certificate? ›

The most important parts of the certificate are the digital signature of the CA and the CA's name because these are used to verify the authenticity of the individual and the authenticity of the certificate.

What are 3 things included in a digital certificate? ›

A digital certificate contains the name of the certificate holder, a serial number, expiration dates, a copy of the certificate holder's public key (used for encrypting messages and digital signatures) and the digital signature of the certificate-issuing authority (CA) so that a recipient can verify that the ...

What do digital certificates verify? ›

Digital certificates are issued by trusted parties, called certificate authorities, to verify the identity of an entity, such as a client or server. The digital certificate serves two purposes: it verifies the owner's identity and it makes the owner's public key available.

What is digital signature with example? ›

The most common example is a wet signature scanned by an electronic device and then inserted into a document. Another example of a simple digital signature is the email signature that we often add at the end of the email, and check the terms and conditions box in the software installation process.

What are the 3 steps in creating a digital signature? ›

How the digital signature process works
  1. # Create the document. The document is created with whatever tool is used in the organization. ...
  2. # 2. Upload the document. With digital signatures, there are numerous options out there. ...
  3. # 3. Send a signature request. Create a signature request to send the document to the signers.
May 26, 2021

How are digital signatures verified? ›

When a digital signature is verified, the signature is decrypted using the public key to produce the original hash value. The data that was signed is hashed. If the two hash values match, then the signature has been verified.

What is the difference between electronic signature and digital signature? ›

Although both electronic signatures and digital signatures add authenticity and integrity to documents, they do so in different ways. Digital signatures make it possible to identify specific documents, whereas eSignatures demonstrate the intent of a signatory to be legally bound by the terms within a specific document.

What is the prime objective of code signing? ›

There are two main reasons for digitally signing code: To provide users with the identity of the organization publishing the signed file. To provide a means to verify the integrity of the file – that is to say, that it was not corrupted or maliciously altered since it was signed.

Who needs code signing? ›

Software Vendors

Developers of software are often required to sign code to support installation. Operating systems like Windows and macOS will warn users if software or drivers are not signed.

Are digital certificates worth it? ›

Earning a digital marketing certificate can be a valuable investment in your career, particularly if you are looking to transition into the field or want to build upon your existing skills.

What are the six main elements included on a digital certificate? ›

A digital certificate includes six main elements, including: 1) Certificate owner's identifying information, such as name, organization address, and so on 2) Certificate owner's public key 3) Dates between which the certificate is valid 4) Serial number of the certificate 5) Name of the certificate issuer 6) Digital ...

What are the two approaches of digital signature? ›

There are two possibilities, sign-then-encrypt and encrypt-then-sign. The receiver after receiving the encrypted data and signature on it, first verifies the signature using sender's public key. After ensuring the validity of the signature, he then retrieves the data through decryption using his private key.

What are the common types of digital certificates? ›

Different types of digital certification

There are three main types of public key certificates: TLS/SSL (Transport Layer Security/Secure Sockets Layer) certificates, client certificates, and code signing certificates. There are also variations within each type of certificate.

What can a digital signature certificate be used for? ›

It helps companies and enterprises to encrypt and upload their documents on web portals. One can also use this certificate to encrypt their personal data and send the same securely. Encrypt DSC is commonly suitable for e-commerce documents, e-tender filing documents, legal documents, and other confidential records.

What is the purpose of code signing? ›

Code signing does two things: it confirms who the author of the software is and proves that the code has not been altered or tampered with after it was signed. Both are extremely important for building trust from customers and safely distributing your software.

How do I get a certificate for code signing? ›

Getting a code signing certificate issued requires three main steps to be followed:
  1. Generating the CSR (Certificate Signing Request).
  2. Completion of Validation.
  3. Downloading the issued code signing certificate.

What is an example of a digital signature in real life? ›

The most common example is a wet signature scanned by an electronic device and then inserted into a document. Another example of a simple digital signature is the email signature that we often add at the end of the email, and check the terms and conditions box in the software installation process.

What is the difference between image signing and code signing? ›

Image signing is where an organization can sign their image before they push it to the container so that the customer can use it safely. Similar to how malicious activity can be caught by code signing, when a user tries to install or execute the file, the signature will first be verified.

What is the value of code signing? ›

Signing your code ensures that it has not been tampered with and that it comes from you. Signing it with a DigiCert Code Signing Certificate shows that you are trusted by the leader in code signing security and helps ensure a safe, secure experience for you and your customers.

How many times can you use a code signing certificate? ›

You can sign as many applications with a Code Signing Certificate as you wish, provided that the applications are used for and distributed by the organization that owns the certificate.


Top Articles
Latest Posts
Article information

Author: Dan Stracke

Last Updated: 12/17/2023

Views: 5645

Rating: 4.2 / 5 (43 voted)

Reviews: 82% of readers found this page helpful

Author information

Name: Dan Stracke

Birthday: 1992-08-25

Address: 2253 Brown Springs, East Alla, OH 38634-0309

Phone: +398735162064

Job: Investor Government Associate

Hobby: Shopping, LARPing, Scrapbooking, Surfing, Slacklining, Dance, Glassblowing

Introduction: My name is Dan Stracke, I am a homely, gleaming, glamorous, inquisitive, homely, gorgeous, light person who loves writing and wants to share my knowledge and understanding with you.