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Cybersecurity · head to head

Cosign vs Silent Eight

Cosign logo

Cosign

Cybersecurity

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

From
Free
Rated
-
Full reviewWebsite
Silent Eight logo

Silent Eight

Cybersecurity

AI adjudication of sanctions screening and AML alerts

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.; Silent Eight automated disposition has to clear model risk governance and a regulator, and the shadow running period before auto-close is permitted can consume most of the first year of the contract.
  • They diverge on capability: Cosign covers Keyless signing, Silent Eight covers Alert adjudication.
  • Prices and features above were last checked on 1 September 2026.

Where they differ

Only the attributes on which Cosign and Silent Eight actually diverge.

Attributes where Cosign and Silent Eight differ
AttributeCosignSilent Eight
Starting priceFreeOn request
Pricing modelOpen source, no licence feequote
Free tierYesNo
PlatformsmacOS, Linux, Windows, DockerWeb, 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 Silent Eight

  • Alert adjudication
  • Narrative generation
  • Name screening automation
  • Quality assurance
  • Shadow mode
  • Model transparency reporting

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

Silent Eight

  • A bank whose level one screening team spends most of its time closing obvious false name matchesnot Cosign
  • A payments institution with alert volumes growing faster than it can recruit and train analystsnot Cosign
  • A compliance function asked by a regulator to demonstrate consistency of alert decisions across offshore teamsnot Cosign
  • An institution that has just tightened screening thresholds after an enforcement action and cannot staff the resulting alert increasenot 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.

Silent Eight

  • Automated disposition has to clear model risk governance and a regulator, and the shadow running period before auto-close is permitted can consume most of the first year of the contract.
  • It does not improve detection, so an institution with a poorly tuned monitoring system automates the handling of bad alerts rather than fixing why they exist.
  • Pricing is tied to alert volume, which means efficiency gains elsewhere that reduce alerts also reduce the vendor bill in a way sales teams structure minimums against.
  • The headcount saving is only realised if the institution actually reduces the analyst pool, and many banks redeploy rather than cut, leaving the business case unrealised on paper.
  • As a mid-sized private vendor serving tier one banks, concentration risk cuts both ways; the loss of one large client materially affects the company, and buyers should ask about financial stability during diligence.

Pricing, plan by plan

Cosign

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

Silent Eight

On request
  • Iris$undefined/year
    • Priced by alert volume adjudicated
    • Deploys against existing screening and monitoring systems
    • Shadow mode evaluation period

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 Silent Eight if

  • You need alert adjudication.
  • You work on Web, Linux.
  • You also want narrative generation.
Silent Eight review

Questions people ask

Is Cosign or Silent Eight better?
Neither clearly leads. Cosign starts at Free and Silent Eight at On request, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Cosign or Silent Eight?
Cosign has a free tier; the other does not. Paid plans start at Free for Cosign and On request for Silent Eight.
Does Cosign or Silent Eight run on more platforms?
Cosign runs on macOS, Linux, Windows, Docker. Silent Eight runs on Web, Linux.
Can I use Cosign for free?
Yes. Cosign has a free tier, so you can try it without paying. Silent Eight 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 Silent Eight is typically brought in for.
What can Cosign do that Silent Eight cannot?
Cosign covers Keyless signing, Key and KMS signing, Registry-native storage, In-toto attestations. Silent Eight covers Alert adjudication, Narrative generation, Name screening automation, Quality assurance.

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.

Silent Eight: Does Silent Eight replace our screening system?

No. It consumes alerts from your existing screening and monitoring systems and decides them. The detection layer stays where it is.

Cosign: Is signing alone enough?

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

Silent Eight: Will a regulator accept AI closing alerts?

It depends on your jurisdiction and your model governance evidence. Banks typically run extended shadow mode first and phase auto-closure by alert type.

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.

Silent Eight: Where is the company based?

Singapore, with offices in New York, London and Warsaw.

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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