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Cybersecurity · head to head

Cosign vs Keeper Password Manager

Cosign logo

Cosign

Cybersecurity

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

From
Free
Rated
-
Full reviewWebsite
Keeper Password Manager logo

Keeper Password Manager

Cybersecurity

Cybersecurity starts here

From
Free
Rated
-
Full reviewWebsite

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.; Keeper Password Manager free tier limited to 10 passwords on one device only
  • They diverge on capability: Cosign covers Keyless signing, Keeper Password Manager covers Zero-knowledge security.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Cosign and Keeper Password Manager actually diverge.

Attributes where Cosign and Keeper Password Manager differ
AttributeCosignKeeper Password Manager
Pricing modelOpen source, no licence feeUnknown
PlatformsmacOS, Linux, Windows, DockerWeb, iOS, Android, Windows, macOS
FoundedUnknown2011

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 Keeper Password Manager

  • Zero-knowledge security
  • Password vault
  • BreachWatch dark web monitoring
  • Secure file storage
  • One-time share
  • Emergency access
  • Passkey support
  • Secrets Manager

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

Keeper Password Manager

  • Password Managernot Cosign
  • Secrets Managementnot Cosign
  • Privileged Accessnot 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.

Keeper Password Manager

  • Free tier limited to 10 passwords on one device only
  • Personal and Family plans lack team collaboration features
  • Higher per-user cost for small teams compared to some competitors

Pricing, plan by plan

Cosign

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

Keeper Password Manager

Free
  • Personal$34.99/year
  • Family$74.99/year
  • Business Starter$2/user per month
  • Business$3.75/user per month

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 Keeper Password Manager if

  • You need zero-knowledge security.
  • You want to start without paying.
  • You work on Web, iOS, Android, Windows, macOS.
  • You also want password vault.
Keeper Password Manager review

Questions people ask

Is Cosign or Keeper Password Manager better?
Neither clearly leads. Cosign starts at Free and Keeper Password Manager at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Cosign or Keeper Password Manager?
Cosign starts at Free and Keeper Password Manager at Free.
Does Cosign or Keeper Password Manager run on more platforms?
Cosign runs on macOS, Linux, Windows, Docker. Keeper Password Manager runs on Web, iOS, Android, Windows, macOS.
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 Keeper Password Manager is typically brought in for.
What can Cosign do that Keeper Password Manager cannot?
Cosign covers Keyless signing, Key and KMS signing, Registry-native storage, In-toto attestations. Keeper Password Manager covers Zero-knowledge security, Password vault, BreachWatch dark web monitoring, Secure file storage.

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.

Keeper Password Manager: Does Keeper offer a free tier?

Keeper's free version stores only 10 passwords on a single mobile device with no cross-device sync and is effectively a trial.

Source
Cosign: Is signing alone enough?

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

Keeper Password Manager: What does Keeper Business cost?

Keeper Business Starter costs $2 per user per month for 5-10 users. Keeper Business costs $3.75 per user per month for unlimited users.

Source
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.

Keeper Password Manager: Does Keeper Enterprise include SSO?

Yes. Keeper Enterprise includes single sign-on capabilities along with compliance and reporting features at $6 per user per month.

Source
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.

Keeper Password Manager: What security features does Keeper include?

Keeper uses zero-knowledge encryption where the company cannot access passwords, plus advanced features like privileged access management and session recording on Enterprise Plus.

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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