Softwr

Cybersecurity · head to head

Cosign vs PublicInput

Cosign logo

Cosign

Cybersecurity

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

From
Free
Free plan
Yes
Full reviewWebsite
PublicInput logo

PublicInput

Government

Inclusive Community Engagement

From
$400/month
Free plan
No
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.; PublicInput all three plans, Listen, Engage and Engage Plus, are listed as Request Pricing with no published rate, minimum or cost driver
  • They diverge on capability: Cosign covers Keyless signing, PublicInput covers Virtual Public Meetings.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Cosign and PublicInput actually diverge.

Attributes where Cosign and PublicInput differ
AttributeCosignPublicInput
Starting priceFree$400/month
Pricing modelOpen source, no licence feesubscription
Free tierYesNo
PlatformsmacOS, Linux, Windows, DockerWeb, Ios, Android
CategoryCybersecurityGovernment
FoundedUnknown2014

Identical on both: user rating (Not yet rated).

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 PublicInput

  • Virtual Public Meetings
  • Online Surveys
  • Comment Management
  • Multi-language Support
  • Engagement Analytics
  • Zoom
  • Microsoft Teams
  • GovDelivery

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

PublicInput

  • Civic engagementnot Cosign
  • Government consultationnot Cosign
  • Public input collectionnot 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.

PublicInput

  • All three plans, Listen, Engage and Engage Plus, are listed as Request Pricing with no published rate, minimum or cost driver
  • HTML and CSS customization, custom workflows and approvals, and external system integration with Accela and ESRI are listed as Enterprise Capabilities rather than core platform features
  • Public meetings functionality is sold under a separate Meetings plan rather than being included with the Engagement plans
  • Getting a plan requires booking a consultation and a tailored demo rather than self serve signup

Pricing, plan by plan

Cosign

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

PublicInput

$400/month
  • Enterprise$400/month
    • Virtual Meetings
    • Surveys
    • Comment Management

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 PublicInput if

  • You need virtual public meetings.
  • You work on Web, Ios, Android.
  • You also want online surveys.
PublicInput review

Questions people ask

Is Cosign or PublicInput better?
Neither clearly leads. Cosign starts at Free and PublicInput at $400/month, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Cosign or PublicInput?
Cosign has a free tier; the other does not. Paid plans start at Free for Cosign and $400/month for PublicInput.
Does Cosign or PublicInput run on more platforms?
Cosign runs on macOS, Linux, Windows, Docker. PublicInput runs on Web, Ios, Android.
Can I use Cosign for free?
Yes. Cosign has a free tier, so you can try it without paying. PublicInput starts at $400/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 PublicInput is typically brought in for.
What can Cosign do that PublicInput cannot?
Cosign covers Keyless signing, Key and KMS signing, Registry-native storage, In-toto attestations. PublicInput covers Virtual Public Meetings, Online Surveys, Comment Management, Multi-language Support.

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.

PublicInput: How much does PublicInput cost?

PublicInput does not publish pricing on their website. Customers must request a demo or book a meeting to receive a quote based on their specific needs.

Source
Cosign: Is signing alone enough?

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

PublicInput: What pricing plans does PublicInput offer?

PublicInput offers Engagement Plans and Meetings Plans, but specific pricing for each plan is not publicly available and requires contacting their sales team.

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.

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.

Share

Related pages

More on Cosign

More on PublicInput

Keep looking

Other head to heads