Cybersecurity · head to head
Cosign vs Microsoft Sentinel
Cosign
Cybersecurity
Signs and verifies container images and artifacts, with or without managing keys
- From
- Free
- Rated
- -
The short version
- Each has a real cost: Cosign keyless signing inherits every weakness of the identity provider behind it. Sigstore’s own threat model states that if an identity provider is compromised, Sigstore will issue certificates to those identities, so a compromised account produces perfectly valid signatures.; Microsoft Sentinel billing is driven by the volume of log data ingested per day, so cost scales with log noise rather than with users or protected assets
- They diverge on capability: Cosign covers Keyless signing, Microsoft Sentinel covers AI-powered analytics.
- Prices and features above were last checked on 31 August 2026.
Where they differ
Only the attributes on which Cosign and Microsoft Sentinel actually diverge.
| Attribute | Cosign | Microsoft Sentinel |
|---|---|---|
| Pricing model | Open source, no licence fee | usage-based |
| Platforms | macOS, Linux, Windows, Docker | Web, Api |
| Founded | Unknown | 1975 |
Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated), category (Cybersecurity).
What each one covers
Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.
Only in Cosign
- Keyless signing
- Key and KMS signing
- Registry-native storage
- In-toto attestations
- Offline verification
- Trusted root and signing config
Only in Microsoft Sentinel
- AI-powered analytics
- Fusion detection
- UEBA
- Automated response playbooks
- Threat intelligence
- Hunting queries
- Workbooks
- Incident management
What people use each for
The jobs each tool is most often brought in to do.
Cosign
- Signing container images in a build pipeline without managing long-lived private keysnot Microsoft Sentinel
- Attaching a signed bill of materials to a release so consumers can verify its provenancenot Microsoft Sentinel
- Meeting a customer or regulatory requirement for signed artifactsnot Microsoft Sentinel
- Verifying third-party images before they enter an internal registrynot Microsoft Sentinel
Microsoft Sentinel
- Cloud-based security information and event management (SIEM)not Cosign
- Extended detection and response (XDR) across enterprise infrastructurenot Cosign
- Data ingestion and long-term security analyticsnot Cosign
Where each one falls short
Documented limitations, not opinions. Every one is a constraint you would hit in normal use.
Cosign
- Keyless signing inherits every weakness of the identity provider behind it. Sigstore’s own threat model states that if an identity provider is compromised, Sigstore will issue certificates to those identities, so a compromised account produces perfectly valid signatures.
- A signature proves who signed, never whether they should have. The documentation is explicit that Sigstore cannot determine authorisation, so every consumer must write and maintain their own identity and issuer policy or verification means nothing.
- Nothing is enforced without an admission controller. Signing changes what you can prove, not what runs, and the official policy controller has a small maintainer base for a component sitting in a cluster admission path.
- Upgrades break pipelines. Version 3 changed defaults, version 4 is announced as removing legacy functionality and roughly half the command line flags, and two official client libraries still lacked support for the new log format as of mid 2026.
- Signatures do not expire. An artifact signed before a maintainer account was compromised and one signed after are indistinguishable unless somebody is actively monitoring the transparency log, and almost nobody is.
Microsoft Sentinel
- Billing is driven by the volume of log data ingested per day, so cost scales with log noise rather than with users or protected assets
- Commitment tier discounts require reserving daily ingestion capacity in advance, and a tier cannot be downgraded until 31 days have passed
- Commitment tiers start at 100 GB per day, above what smaller estates ingest
- Charges for Log Analytics, Logic Apps and Machine Learning are billed separately on top of Sentinel itself
- The free allowance is only up to 5 MB per user per day for selected Microsoft 365 security logs
- Promotional commitment pricing is time limited and locks in only until a stated end date
Pricing, plan by plan
Cosign
Free- CosignFree
- Apache-2.0
- Public Sigstore infrastructure free to use
- No usage limits published
Microsoft Sentinel
Free- Pay-As-You-Go$2.46/day
- Per GB ingested
- 90-day retention
- First 31 days free for new workspaces
- Commitment TiersFree
- 100GB to 50TB tiers
- Up to 65% discount
- Predictable billing
- Microsoft 365 E5Free
- Free data ingestion for M365 logs
- Bundled with E5 license
Which should you pick?
Choose Cosign if
- You need keyless signing.
- You want to start without paying.
- You work on macOS, Linux, Windows, Docker.
- You also want key and kms signing.
Choose Microsoft Sentinel if
- You need ai-powered analytics.
- You want to start without paying.
- You work on Web, Api.
- You also want fusion detection.
Questions people ask
- Is Cosign or Microsoft Sentinel better?
- Neither clearly leads. Cosign starts at Free and Microsoft Sentinel at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
- Which is cheaper, Cosign or Microsoft Sentinel?
- Cosign starts at Free and Microsoft Sentinel at Free.
- Does Cosign or Microsoft Sentinel run on more platforms?
- Cosign runs on macOS, Linux, Windows, Docker. Microsoft Sentinel runs on Web, Api.
- Can I use Cosign for free?
- Both have a free tier, so you can try either at no cost before committing.
- What is Cosign best used for?
- Cosign is most often used for signing container images in a build pipeline without managing long-lived private keys, attaching a signed bill of materials to a release so consumers can verify its provenance, meeting a customer or regulatory requirement for signed artifacts, verifying third-party images before they enter an internal registry. Of those, signing container images in a build pipeline without managing long-lived private keys and attaching a signed bill of materials to a release so consumers can verify its provenance are not what Microsoft Sentinel is typically brought in for.
- What can Cosign do that Microsoft Sentinel cannot?
- Cosign covers Keyless signing, Key and KMS signing, Registry-native storage, In-toto attestations. Microsoft Sentinel covers AI-powered analytics, Fusion detection, UEBA, Automated response playbooks.
Answered from the vendors’ own pages
Cosign: Does Cosign tell me if an image is vulnerable?
No. It has no vulnerability knowledge whatsoever. It can carry an SBOM as a signed attestation but never reads it. Pair it with a scanner.
Microsoft Sentinel: How is Microsoft Sentinel pricing calculated?
Microsoft Sentinel uses a pay-as-you-go usage-based model where you pay only for data ingested, stored, and consumed. Flexible commitment tiers are available to reduce total cost of ownership, with specific rates not published on the public pricing page. Source: https://www.microsoft.com/security/business/siem-and-xdr/microsoft-sentinel/
SourceCosign: Is signing alone enough?
No. Verification is a command somebody runs. Without an admission controller enforcing it, an unsigned image still runs.
Microsoft Sentinel: Does Microsoft Sentinel require an Azure subscription?
Yes, Microsoft Sentinel requires a Microsoft Azure subscription to operate. Pricing is handled through Azure and varies based on data consumption and the commitment tier you select. Source: https://www.microsoft.com/security/business/siem-and-xdr/microsoft-sentinel/
SourceCosign: What does a bare cosign verify actually prove?
Very little. Without a pinned certificate identity and OIDC issuer, it accepts a valid signature from any identity at all.
Cosign: What is the risk of keyless signing?
Your OIDC provider becomes the root of trust. Compromise of that account yields genuine, verifiable signatures, so account security is the control that matters.
Cosign: Should we expect breaking changes?
Yes. Version 4 is announced to remove roughly half the flags, and a post-quantum migration is named as a further breaking change after that.
Related pages
More on Microsoft Sentinel
Other head to heads
- Cosign vs Sigstore
- Cosign vs Syft
- Cosign vs Chainguard
- Cosign vs HashiCorp Vault
- Cosign vs Infisical
- Cosign vs OWASP ZAP
- Cosign vs Wireshark
- Cosign vs Bitwarden
- Cosign vs Semgrep
- Cosign vs Trivy
- Cosign vs authentik
- Cosign vs Microsoft Intune
- Cosign vs Netwrix
- Cosign vs NordVPN
- Cosign vs Omada Identity
- Cosign vs Ory
- Cosign vs ProtonVPN
- Cosign vs Grype
- Cosign vs Bitdefender Total Security
- Cosign vs Norton 360
- Cosign vs 1Password
- Cosign vs LastPass
- Cosign vs LogRhythm SIEM
- Cosign vs IBM QRadar
- Cosign vs CrowdStrike Falcon
- Cosign vs Splunk Enterprise Security
- Cosign vs SentinelOne Singularity
- Cosign vs Legit Security
- Cosign vs Sysdig
- Cosign vs Endor Labs
- Cosign vs Proton Mail
- Cosign vs Veriff
- Cosign vs Brave Browser
- Cosign vs March Networks
- Cosign vs Salient CompleteView
- Cosign vs Sumsub
- Microsoft Sentinel vs Sigstore
- Microsoft Sentinel vs Syft
- Microsoft Sentinel vs Chainguard
- Microsoft Sentinel vs HashiCorp Vault
- Microsoft Sentinel vs Infisical
- Microsoft Sentinel vs OWASP ZAP
- Microsoft Sentinel vs Wireshark
- Microsoft Sentinel vs Bitwarden
- Microsoft Sentinel vs Semgrep
- Microsoft Sentinel vs Trivy
- Microsoft Sentinel vs authentik
- Microsoft Sentinel vs Microsoft Intune
- Microsoft Sentinel vs Netwrix
- Microsoft Sentinel vs NordVPN
- Microsoft Sentinel vs Omada Identity
- Microsoft Sentinel vs Ory
- Microsoft Sentinel vs ProtonVPN
- Microsoft Sentinel vs Grype
- Microsoft Sentinel vs Bitdefender Total Security
- Microsoft Sentinel vs Norton 360
- Microsoft Sentinel vs 1Password
- Microsoft Sentinel vs LastPass
- Microsoft Sentinel vs LogRhythm SIEM
- Microsoft Sentinel vs IBM QRadar
- Microsoft Sentinel vs CrowdStrike Falcon
- Microsoft Sentinel vs Splunk Enterprise Security
- Microsoft Sentinel vs SentinelOne Singularity
- Microsoft Sentinel vs Legit Security
- Microsoft Sentinel vs Sysdig
- Microsoft Sentinel vs Endor Labs
- Microsoft Sentinel vs Proton Mail
- Microsoft Sentinel vs Veriff
- Microsoft Sentinel vs Brave Browser
- Microsoft Sentinel vs March Networks
- Microsoft Sentinel vs Salient CompleteView
- Microsoft Sentinel vs Sumsub