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Cybersecurity · head to head

Cosign vs Entrust Identity as a Service

Cosign logo

Cosign

Cybersecurity

Signs and verifies container images and artifacts, with or without managing keys

From
Free
Rated
-
Full reviewWebsite
Entrust Identity as a Service logo

Entrust Identity as a Service

Cybersecurity

Workforce and customer authentication from a certificate authority

From
$2/month
Rated
-
Full reviewWebsite

The short version

  • Only Cosign has a free tier, so it costs nothing to try first.
  • 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.; Entrust Identity as a Service the application integration catalogue is smaller than that of the dedicated identity vendors, so uncommon SaaS applications more often need custom SAML configuration rather than a template.
  • They diverge on capability: Cosign covers Keyless signing, Entrust Identity as a Service covers Multi-factor authentication.
  • Prices and features above were last checked on 1 September 2026.

Where they differ

Only the attributes on which Cosign and Entrust Identity as a Service actually diverge.

Attributes where Cosign and Entrust Identity as a Service differ
AttributeCosignEntrust Identity as a Service
Starting priceFree$2/month
Pricing modelOpen source, no licence feePer user per month
Free tierYesNo
PlatformsmacOS, Linux, Windows, DockerWeb, iOS, Android, Windows, Linux

Identical on both: 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 Entrust Identity as a Service

  • Multi-factor authentication
  • Single sign-on
  • Adaptive authentication
  • Passwordless login
  • Credential lifecycle
  • Derived PIV credentials
  • Directory integration

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 Entrust Identity as a Service
  • Attaching a signed bill of materials to a release so consumers can verify its provenancenot Entrust Identity as a Service
  • Meeting a customer or regulatory requirement for signed artifactsnot Entrust Identity as a Service
  • Verifying third-party images before they enter an internal registrynot Entrust Identity as a Service

Entrust Identity as a Service

  • A government agency needing derived mobile credentials from an existing PIV smart card estatenot Cosign
  • A bank that must support hardware tokens for corporate treasury users alongside push authentication for staffnot Cosign
  • An organisation already buying Entrust certificates that wants credential issuance and authentication from one vendornot Cosign
  • A defence supplier required to use certificate-based authentication that mainstream cloud identity products handle poorlynot 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.

Entrust Identity as a Service

  • The application integration catalogue is smaller than that of the dedicated identity vendors, so uncommon SaaS applications more often need custom SAML configuration rather than a template.
  • Developer experience for customer identity use cases is behind the specialists, and teams building consumer signup flows will find the APIs and documentation less complete.
  • Advanced capabilities including adaptive authentication and credential management sit above the published entry price, so the two dollar figure rarely reflects what a regulated buyer actually spends.
  • There are two overlapping products, Identity as a Service and Identity Enterprise, and choosing wrongly at the start means a migration later rather than a licence change.
  • Identity governance, access certification and privileged access are not covered, so an organisation with audit-driven access review requirements needs a second vendor alongside it.

Pricing, plan by plan

Cosign

Free
  • CosignFree
    • Apache-2.0
    • Public Sigstore infrastructure free to use
    • No usage limits published

Entrust Identity as a Service

$2/month
  • Workforce Standard$2/month
    • Multi-factor authentication
    • Single sign-on
    • Directory integration
  • Higher tiers$undefined/month
    • Adaptive risk-based authentication
    • Certificate and smart card credential management
    • Derived PIV credentials

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.
Cosign review

Choose Entrust Identity as a Service if

  • You need multi-factor authentication.
  • You work on Web, iOS, Android, Windows, Linux.
  • You also want single sign-on.
Entrust Identity as a Service review

Questions people ask

Is Cosign or Entrust Identity as a Service better?
Neither clearly leads. Cosign starts at Free and Entrust Identity as a Service at $2/month, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Cosign or Entrust Identity as a Service?
Cosign has a free tier; the other does not. Paid plans start at Free for Cosign and $2/month for Entrust Identity as a Service.
Does Cosign or Entrust Identity as a Service run on more platforms?
Cosign runs on macOS, Linux, Windows, Docker. Entrust Identity as a Service runs on Web, iOS, Android, Windows, Linux.
Can I use Cosign for free?
Yes. Cosign has a free tier, so you can try it without paying. Entrust Identity as a Service starts at $2/month.
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 Entrust Identity as a Service is typically brought in for.
What can Cosign do that Entrust Identity as a Service cannot?
Cosign covers Keyless signing, Key and KMS signing, Registry-native storage, In-toto attestations. Entrust Identity as a Service covers Multi-factor authentication, Single sign-on, Adaptive authentication, Passwordless login.

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.

Entrust Identity as a Service: Is MFA included or extra?

Multi-factor authentication is included in the workforce bundles rather than sold separately, which is not true of every competitor. Adaptive risk-based authentication sits in higher tiers.

Cosign: Is signing alone enough?

No. Verification is a command somebody runs. Without an admission controller enforcing it, an unsigned image still runs.

Entrust Identity as a Service: Does it do identity governance?

No. Access certification, role mining and joiner-mover-leaver governance require a separate product such as SailPoint or Saviynt.

Cosign: 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.

Entrust Identity as a Service: Why choose this over Okta or Entra ID?

Almost always because of PKI, smart cards or derived credentials. Without that requirement the mainstream platforms are the stronger general purpose choice.

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.

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