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Cybersecurity · head to head

Cosign vs Rhombus Systems

Cosign logo

Cosign

Cybersecurity

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

From
Free
Rated
-
Full reviewWebsite
Rhombus Systems logo

Rhombus Systems

Cybersecurity

Cloud-managed cameras, sensors and access control with a per-camera annual licence

From
$149/year
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.; Rhombus Systems the per-camera annual licence never ends and a camera without an active licence stops working, so the total cost over a ten-year hardware life is several times the hardware price.
  • They diverge on capability: Cosign covers Keyless signing, Rhombus Systems covers On-camera storage.
  • Prices and features above were last checked on 1 September 2026.

Where they differ

Only the attributes on which Cosign and Rhombus Systems actually diverge.

Attributes where Cosign and Rhombus Systems differ
AttributeCosignRhombus Systems
Starting priceFree$149/year
Pricing modelOpen source, no licence feePer camera per year licence plus hardware
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 Rhombus Systems

  • On-camera storage
  • No NVR or server
  • AI search
  • Access control
  • Environmental sensors
  • Unlimited users
  • Ten year hardware warranty
  • Optional cloud archiving

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

Rhombus Systems

  • A school district running video across dozens of buildings with no local IT at each sitenot Cosign
  • A clinic group needing door access and cameras in one console under a single audit trailnot Cosign
  • A logistics operator that wants to search for a specific vehicle across sites without scrubbing footagenot Cosign
  • An office estate replacing ageing NVRs where nobody remains who knows how to maintain themnot 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.

Rhombus Systems

  • The per-camera annual licence never ends and a camera without an active licence stops working, so the total cost over a ten-year hardware life is several times the hardware price.
  • Cameras must be Rhombus, so there is no reuse of existing IP cameras and migrating away means replacing every device rather than changing software.
  • Cloud archiving is priced separately by retention and stream count, and long retention on multisensor cameras runs into five figures per camera, which can dwarf everything else in the quote.
  • On-camera storage is the default retention, so a camera physically stolen or destroyed takes its unarchived footage with it unless cloud archiving was paid for on that camera.
  • Analytics and integrations are good for mid-market needs but shallower than a dedicated enterprise VMS with a large third-party ecosystem, so specialist requirements like advanced LPR or forensic search hit limits.

Pricing, plan by plan

Cosign

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

Rhombus Systems

$149/year
  • Professional$149/year
    • Per camera per year
    • Cloud console and management
    • On-camera storage retention
  • Enterprise$199/year
    • Per camera per year
    • Everything in Professional
    • Flexible cloud archiving options
  • Cloud archiving$undefined/year
    • Priced separately by retention period and stream count
    • Multisensor cameras cost several times a single sensor camera
    • Long retention on multisensor models can reach five figures per camera

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 Rhombus Systems if

  • You need on-camera storage.
  • You work on Web, iOS, Android.
  • You also want no nvr or server.
Rhombus Systems review

Questions people ask

Is Cosign or Rhombus Systems better?
Neither clearly leads. Cosign starts at Free and Rhombus Systems at $149/year, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Cosign or Rhombus Systems?
Cosign has a free tier; the other does not. Paid plans start at Free for Cosign and $149/year for Rhombus Systems.
Does Cosign or Rhombus Systems run on more platforms?
Cosign runs on macOS, Linux, Windows, Docker. Rhombus Systems runs on Web, iOS, Android.
Can I use Cosign for free?
Yes. Cosign has a free tier, so you can try it without paying. Rhombus Systems starts at $149/year.
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 Rhombus Systems is typically brought in for.
What can Cosign do that Rhombus Systems cannot?
Cosign covers Keyless signing, Key and KMS signing, Registry-native storage, In-toto attestations. Rhombus Systems covers On-camera storage, No NVR or server, AI search, Access control.

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.

Rhombus Systems: Do I need an NVR or a server?

No. Cameras record on board and connect directly to the cloud console, which is the main operational reason organisations pick it.

Cosign: Is signing alone enough?

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

Rhombus Systems: What does the licence cost?

Roughly $149 per camera per year for Professional and about $199 for Enterprise, typically sold in one, three, five or ten year terms.

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.

Rhombus Systems: Is cloud storage included?

No. On-camera storage is the default. Cloud archiving is a separate charge priced by retention duration and number of streams.

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.

Rhombus Systems: Can I use my existing cameras?

No. The platform works only with Rhombus hardware, which is the trade-off for the zero-server architecture.

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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