Softwr

Cybersecurity · head to head

Cosign vs DemandStar

Cosign logo

Cosign

Cybersecurity

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

From
Free
Free plan
Yes
Full reviewWebsite
DemandStar logo

DemandStar

Government

Bid distribution network that is free for government agencies and charges the suppliers instead

From
Free
Free plan
Yes
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.; DemandStar coverage is opt-in by agency, so a supplier paying for a state tier receives only participating agencies and must still monitor other portals for the rest.
  • They diverge on capability: Cosign covers Keyless signing, DemandStar covers Free for agencies.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Cosign and DemandStar actually diverge.

Attributes where Cosign and DemandStar differ
AttributeCosignDemandStar
Pricing modelOpen source, no licence feeFree for agencies, per year by geographic coverage for suppliers
PlatformsmacOS, Linux, Windows, DockerWeb
CategoryCybersecurityGovernment

Identical on both: starting price (Free), free tier (Yes), 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 DemandStar

  • Free for agencies
  • Commodity code matching
  • eBidding
  • Plan holder lists
  • Supplier registration
  • Geographic subscription tiers

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

DemandStar

  • A city purchasing officer who wants wider bid distribution without running a procurement to buy softwarenot Cosign
  • A contractor who works in three adjacent counties and wants notifications only for that footprintnot Cosign
  • An agency needing sealed electronic bid submission to replace paper deliveries to the clerknot Cosign
  • A supplier testing whether public sector work is viable before committing to a national subscriptionnot 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.

DemandStar

  • Coverage is opt-in by agency, so a supplier paying for a state tier receives only participating agencies and must still monitor other portals for the rest.
  • The free supplier tier charges around 5 US dollars per bid document download, which turns an apparently free plan into a metered one as soon as you actually pursue opportunities.
  • State pricing ranges from roughly 100 to 1,499 US dollars with the variation driven by agency density, so suppliers cannot predict cost from geography alone.
  • Because agencies pay nothing, they have little leverage over the roadmap and features are driven by what makes supplier subscriptions sell.
  • The brand is being folded into Euna OpenBid following the Euna Solutions consolidation, so suppliers and agencies should expect the name and portal to change.

Pricing, plan by plan

Cosign

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

DemandStar

Free
  • Government agencyFree
    • Post unlimited solicitations
    • Access the supplier network
    • eBidding and plan holder lists
  • Supplier freeFree
    • Bid notifications for one agency of your choice
    • Bid document downloads charged around 5 USD each
    • Supplier profile and registration
  • Supplier county$60/year
    • All participating agencies within one county
    • Unlimited bid document access for that county
    • Approximate rate, varies by county
  • Supplier state$100/year
    • All participating agencies within one state
    • Priced from around 100 to 1,499 USD depending on agency density

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 DemandStar if

  • You need free for agencies.
  • You want to start without paying.
  • You also want commodity code matching.
DemandStar review

Questions people ask

Is Cosign or DemandStar better?
Neither clearly leads. Cosign starts at Free and DemandStar at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Cosign or DemandStar?
Cosign starts at Free and DemandStar at Free.
Does Cosign or DemandStar run on more platforms?
Cosign runs on macOS, Linux, Windows, Docker. DemandStar runs on Web.
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 DemandStar is typically brought in for.
What can Cosign do that DemandStar cannot?
Cosign covers Keyless signing, Key and KMS signing, Registry-native storage, In-toto attestations. DemandStar covers Free for agencies, Commodity code matching, eBidding, Plan holder lists.

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.

DemandStar: Is DemandStar free for governments?

Yes, entirely. Agencies post solicitations and access the supplier network at no cost; suppliers fund the platform.

Cosign: Is signing alone enough?

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

DemandStar: What do suppliers pay?

Free for one agency with roughly 5 USD per document download, about 60 USD a year per county, 100 to 1,499 per state, and 2,699 for national coverage.

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.

DemandStar: Who owns DemandStar?

Euna Solutions, the public sector portfolio formerly known as GTY Technology, which also absorbed Bonfire and Ion Wave.

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.

DemandStar: Does it cover every agency?

No. Only agencies that have opted in, which is the main limitation for suppliers buying wide coverage.

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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