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Cybersecurity · head to head

Cosign vs Transmit Security

Cosign logo

Cosign

Cybersecurity

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

From
Free
Rated
-
Full reviewWebsite
Transmit Security logo

Transmit Security

Cybersecurity

Customer identity platform built around passwordless and fraud signals

From
On request
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.; Transmit Security pricing is not published, so it cannot be compared early against competitors that post per monthly active user rates, and the eventual quote often mixes per-user and per-transaction units.
  • They diverge on capability: Cosign covers Keyless signing, Transmit Security covers Passwordless authentication.
  • Prices and features above were last checked on 1 September 2026.

Where they differ

Only the attributes on which Cosign and Transmit Security actually diverge.

Attributes where Cosign and Transmit Security differ
AttributeCosignTransmit Security
Starting priceFreeOn request
Pricing modelOpen source, no licence feequote
Free tierYesNo
PlatformsmacOS, Linux, Windows, DockerWeb, iOS, Android

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 Transmit Security

  • Passwordless authentication
  • Detection and response
  • Identity verification
  • Orchestration
  • Account recovery
  • Bot and automation detection
  • Composable APIs

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

Transmit Security

  • A bank moving a consumer base off passwords to passkeys without losing customers at the migration stepnot Cosign
  • An insurer whose account recovery flow is the main account takeover route and needs risk scoring inside itnot Cosign
  • A retailer that wants bot detection at login rather than only at checkoutnot Cosign
  • An organisation replacing an in-house customer login system that has become an unfunded engineering liabilitynot 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.

Transmit Security

  • Pricing is not published, so it cannot be compared early against competitors that post per monthly active user rates, and the eventual quote often mixes per-user and per-transaction units.
  • Migrating a live consumer identity base is a high risk project, and credential migration constraints mean some users must re-register, which shows up as measurable churn.
  • The vendor is smaller than the identity incumbents, so the partner and systems integrator pool is thinner and staffing a large programme is harder.
  • Workforce identity is not the focus, so an organisation wanting one vendor for employees and customers will still run two platforms.
  • The fraud detection value depends on traffic volume feeding the models, so a smaller deployment gets less benefit from exactly the capability that justified choosing it over a plain identity provider.

Pricing, plan by plan

Cosign

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

Transmit Security

On request
  • Transmit Security Platform$undefined/year
    • Priced per monthly active user or per transaction by service
    • Services licensed individually or as a platform
    • Free developer tier for evaluation

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 Transmit Security if

  • You need passwordless authentication.
  • You work on Web, iOS, Android.
  • You also want detection and response.
Transmit Security review

Questions people ask

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

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.

Transmit Security: Do we have to replace our existing identity provider?

No. The services are composable, so detection and response or verification can be adopted alongside an existing provider such as Okta or Entra ID.

Cosign: Is signing alone enough?

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

Transmit Security: Is fraud detection an extra licence?

It is a separate service, but it is designed to run inside the authentication flow rather than as a bolted-on second vendor. Confirm which services are in your quote.

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.

Transmit Security: Is there a way to try it?

Yes, a free developer tier exists for evaluation, though production use is an enterprise agreement.

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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