What is a code signing certificate and why do I need it?

A code signing certificate is a digital certificate that allows developers to sign their software and applications. It proves the authenticity and integrity of the code, eliminates security warnings, and builds trust with users by confirming that the software hasn't been tampered with since it was signed.

What happens if I don't use code signing for my software?

Without code signing, users will see 'Unknown Publisher' warnings when downloading or running your software. Modern operating systems and browsers flag unsigned software as potentially dangerous, which can significantly reduce user trust and adoption rates.

What types of files can I sign with a code signing certificate?

You can sign various file types including Windows executables (.exe), libraries (.dll), drivers (.sys), installers (.msi), Java applications (.jar), mobile apps, scripts, and other executable code formats depending on the certificate type.

What's the difference between Standard and EV Code Signing certificates?

Standard Code Signing certificates provide basic authentication, while EV (Extended Validation) certificates offer enhanced validation with immediate SmartScreen reputation, better trust indicators, and are stored on secure hardware tokens for maximum security.

How long does it take to get a code signing certificate?

Standard code signing certificates can be issued within 1-3 business days after identity verification. EV code signing certificates may take 3-7 business days due to the more thorough validation process required.

Can I use the same certificate to sign different types of applications?

Yes, most code signing certificates are platform-agnostic and can be used to sign multiple types of applications and files. However, some specialized certificates are designed for specific platforms like iOS or Android app signing.

Code Signing Guide

Code Signing Certificates: Secure Your Software

Code signing certificates digitally sign your software to prove authenticity, eliminate security warnings, and build trust with users by ensuring your applications haven't been tampered with.

My-SSL Security Team

Published December 31, 2024

Updated January 14, 2026

10 min read

What Are Code Signing Certificates?

Code signing certificates are digital certificates that allow software developers to digitally sign their applications, executables, and other code. This cryptographic signature serves as a digital seal of authenticity, proving that the software comes from a verified publisher and hasn't been modified or corrupted since it was signed.

Authenticity

Proves software origin and publisher identity

Integrity

Ensures code hasn't been modified or corrupted

Trust

Builds user confidence and reduces security warnings

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Standard Code Signing Certificate

Starting at $189.99/year

Multi-platform Support
Instant Trust
3-Year Validity
Cryptographic Token Included

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Why Code Signing Is Essential

In today's security-conscious environment, unsigned software faces significant barriers to adoption. Operating systems, browsers, and security software increasingly flag unsigned applications as potentially dangerous.

Without Code Signing

"Unknown Publisher" warnings appear to users
Windows SmartScreen blocks downloads
Antivirus software flags applications as suspicious
App stores reject unsigned applications
Users lose trust and abandon installations

With Code Signing

Your company name appears as the verified publisher
No security warnings or download blocks
Builds Microsoft SmartScreen reputation over time
Higher user adoption and installation rates
Protects against malware injection and tampering

Types of Code Signing Certificates

Standard Code Signing

Basic code signing certificate for individual developers and small teams.

Individual or organization validation
Eliminates security warnings
Software file storage
1-3 business days issuance

EV Code Signing

Extended validation certificate with the highest level of trust and security.

Enhanced business validation
Immediate SmartScreen reputation
Hardware token required
Maximum security and trust

Premium

Purchasing a Certum Code Signing Certificate?

Learn about the identity verification and required documents for Certum Open Source, Standard, and EV Code Signing certificates.

View Certum Code Signing Required Documents →

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Starting at $399.99/year

Hardware Token Included
Immediate SmartScreen Trust
Enhanced Validation
Maximum Security

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Supported Platforms and File Types

Our code signing certificates support a wide range of platforms and file formats, making them suitable for virtually any development environment.

Windows Applications

• Executables (.exe)
• Libraries (.dll)
• Installers (.msi)
• Device drivers (.sys)
• ActiveX controls (.ocx)

Cross-Platform

• Java applications (.jar)
• Adobe AIR apps (.air)
• Microsoft Office macros
• PowerShell scripts
• ClickOnce applications

Mobile & Web

• Android APK files
• Chrome extensions
• Firefox add-ons
• Windows Store apps
• Docker containers

How Code Signing Works

The Code Signing Process

1Developer obtains a code signing certificate from a trusted Certificate Authority
2Certificate is installed on developer's system or hardware token
3Software is signed using the private key, creating a digital signature
4Operating system verifies the signature using the certificate's public key
5If valid, software runs without security warnings

Code Signing Best Practices

Security Guidelines

Keep private keys secure and encrypted
Use hardware tokens for EV certificates
Implement timestamping for longevity
Monitor certificate expiration dates

Development Tips

Sign all executable components
Test signed applications thoroughly
Build SmartScreen reputation gradually
Use consistent publisher information

Sources & References

Official documentation and industry standards cited in this article

Baseline Requirements for Code Signing Certificates
CA/Browser Forum·Standard·Accessed January 2026
Code Signing Best Practices
Microsoft·Documentation·Accessed January 2026
RFC 3161 - Timestamping Authority
IETF·RFC·Accessed January 2026
Apple Developer Code Signing
Apple Inc.·Official·Accessed January 2026