Cosign
Claim this toolCode signing and transparency for containers and binaries using Sigstore.
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Tracked since2026
0 reviews trackedThe Bottom Line
Entry price
Free, no paid tier
Biggest pro
Increases trust and integrity of software artifacts
Biggest con
Requires understanding of OCI registries and signing concepts
TL;DR - Cosign
- Simplifies code signing for containers and binaries.
- Utilizes Sigstore's keyless signing and transparency logs.
- Enhances software supply chain security and integrity.
Pricing: Free forever
Best for: Individuals & startups
What is Cosign?
Cosign is an open-source tool developed as part of the Sigstore project, designed to simplify code signing and enhance transparency for containers and other software artifacts. It aims to make signatures an invisible part of the infrastructure, providing developers with a straightforward way to sign and verify their software.
Cosign supports various signing methods, including "Keyless signing" with the Sigstore public good Fulcio certificate authority and Rekor transparency log, hardware and KMS signing, and signing with Cosign-generated encrypted keypairs. It facilitates container signing, verification, and storage within an OCI registry, and also allows users to bring their own Public Key Infrastructure (PKI). This tool is crucial for developers and organizations looking to secure their software supply chain by ensuring the authenticity and integrity of their deployed artifacts.
By integrating with Sigstore's transparency logs, Cosign provides an immutable record of signing events, making it difficult for malicious actors to tamper with software without detection. Its ease of use, especially with the default keyless signing, lowers the barrier to entry for robust software supply chain security practices.
Available on: Linux, macOS
Pros & Cons
Pros
- Increases trust and integrity of software artifacts
- Simplifies complex code signing processes with keyless signing
- Provides transparency through public logs
- Supports multiple signing methods for flexibility
- Open-source and community-driven
Cons
- Requires understanding of OCI registries and signing concepts
- Personally identifiable information may be stored in public transparency logs during keyless signing
- Newer versions may focus development on sigstore-go, potentially impacting feature velocity for Cosign 2.x
Key Features
Keyless signing with Sigstore Fulcio CA and Rekor transparency logHardware and KMS signing supportSigning with Cosign-generated encrypted private/public keypairsContainer signing, verification, and storage in OCI registriesBring-your-own PKI supportIntegration with public transparency logs for immutable recordsCommand-line interface for signing and verification
Pricing Plans
Pricing checked Aug 28, 2026
Open Source
Free
- Full source code access
- Apache License 2.0 license
- Community support
- Self-hosted
Is Cosign worth the price?
100/100
Cosign's pricing is exceptionally generous as it offers a fully featured 'Open Source' tier completely free of charge.
This makes it an incredibly fair and accessible solution for anyone needing code signing and transparency. It's best for individual developers, small teams, and open-source projects looking for robust security without cost.
Reviews
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Cosign FAQ
How does Cosign enhance the security of software artifacts?
Cosign increases the trust and integrity of software artifacts by enabling code signing and verification. It ensures the authenticity and integrity of deployed artifacts, which is crucial for securing the software supply chain.
What kind of user benefits most from Cosign?
Developers and organizations looking to secure their software supply chain by ensuring the authenticity and integrity of their deployed artifacts benefit most from Cosign. It is particularly useful for those who need to simplify complex code signing processes.
How is Cosign priced?
Cosign is free to use, as it is an open-source tool with no paid plan required. It is developed as part of the Sigstore project, which aims to provide public good services.
Can Cosign be used with existing Public Key Infrastructure?
Yes, Cosign allows users to bring their own Public Key Infrastructure (PKI) for signing. This provides flexibility for organizations that already have established PKI systems.
How does Cosign compare to GitGuardian in terms of functionality?
Cosign focuses on code signing and transparency for containers and binaries to secure the software supply chain. GitGuardian, in contrast, typically focuses on detecting secrets in code repositories to prevent leaks.
Which signing methods does Cosign support?
Cosign supports various signing methods, including keyless signing with the Sigstore public good Fulcio certificate authority and Rekor transparency log. It also supports hardware and KMS signing, and signing with Cosign-generated encrypted keypairs.
Source: github.com