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Cybersecurity · head to head

Cosign vs Milestone XProtect

Cosign logo

Cosign

Cybersecurity

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

From
Free
Rated
-
Full reviewWebsite
Milestone XProtect logo

Milestone XProtect

Cybersecurity

Open platform video management software with perpetual per-device licences

From
Free
Rated
-
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.; Milestone XProtect care Plus is presented as optional but is not in practice: without it, perpetual licences stop receiving version upgrades and eventually you cannot add a current camera because your frozen version does not support it.
  • They diverge on capability: Cosign covers Keyless signing, Milestone XProtect covers Open device support.
  • Prices and features above were last checked on 1 September 2026.

Where they differ

Only the attributes on which Cosign and Milestone XProtect actually diverge.

Attributes where Cosign and Milestone XProtect differ
AttributeCosignMilestone XProtect
Pricing modelOpen source, no licence feeOne-time purchase per device licence, plus annual Care Plus
PlatformsmacOS, Linux, Windows, DockerWindows, Web, iOS, Android

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

  • Open device support
  • Perpetual device licences
  • Federated architecture
  • Failover recording
  • Evidence export
  • Smart Map
  • Integration platform
  • Video summarisation

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

Milestone XProtect

  • A city or transport operator running tens of thousands of cameras across federated sitesnot Cosign
  • An enterprise with mixed legacy camera brands that refuses to standardise on one manufacturernot Cosign
  • A critical infrastructure site needing failover recording servers and tamper-evident evidence exportnot Cosign
  • An integrator building a bespoke security application on top of an open VMS platformnot 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.

Milestone XProtect

  • Care Plus is presented as optional but is not in practice: without it, perpetual licences stop receiving version upgrades and eventually you cannot add a current camera because your frozen version does not support it.
  • Per-device licensing means multi-sensor and multi-imager cameras consume several licences each, so a headline camera count badly understates the true licence cost of a modern design.
  • It is Windows only for servers and needs a properly designed server and storage architecture, so the software price is a fraction of a project that also needs recording servers, storage and an integrator.
  • Complexity requires trained staff or a certified integrator; organisations that install it without either end up running a large deployment on default settings and never using the features they paid for.
  • Milestone retired Kite from its portfolio in favour of Arcules from January 2025, which stranded buyers who had standardised on Kite and is a reminder that the cloud side of the portfolio has changed direction more than once.

Pricing, plan by plan

Cosign

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

Milestone XProtect

Free
  • XProtect Essential+Free
    • Free for up to 8 cameras
    • No recording time limit
    • No vendor support included
  • XProtect Express+$109/one-time
    • Perpetual device licence, distributor list price
    • Single site, single server
    • Care Plus purchased separately per device per year
  • XProtect Professional+$177/one-time
    • Perpetual device licence, distributor list price
    • Multiple recording servers
    • Edge storage retrieval
  • XProtect Expert$282/one-time
    • Perpetual device licence, distributor list price
    • Failover recording servers
    • Advanced video wall and evidence handling

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 Milestone XProtect if

  • You need open device support.
  • You want to start without paying.
  • You work on Windows, Web, iOS, Android.
  • You also want perpetual device licences.
Milestone XProtect review

Questions people ask

Is Cosign or Milestone XProtect better?
Neither clearly leads. Cosign starts at Free and Milestone XProtect at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Cosign or Milestone XProtect?
Cosign starts at Free and Milestone XProtect at Free.
Does Cosign or Milestone XProtect run on more platforms?
Cosign runs on macOS, Linux, Windows, Docker. Milestone XProtect runs on Windows, Web, iOS, Android.
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 Milestone XProtect is typically brought in for.
What can Cosign do that Milestone XProtect cannot?
Cosign covers Keyless signing, Key and KMS signing, Registry-native storage, In-toto attestations. Milestone XProtect covers Open device support, Perpetual device licences, Federated architecture, Failover recording.

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.

Milestone XProtect: Is XProtect really free for small sites?

Essential+ is free for up to eight cameras with no recording time limit, but it comes with no vendor support and no multi-server capability.

Cosign: Is signing alone enough?

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

Milestone XProtect: Are licences perpetual or annual?

Device licences are perpetual. The annual cost is Care Plus, the support and software update contract, which you need to stay on current versions.

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.

Milestone XProtect: What happens if I do not renew Care Plus?

The system keeps recording, but you stop getting version upgrades, and over a few years that blocks you from adding newer cameras.

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.

Milestone XProtect: Who owns Milestone?

Canon. The portfolio also includes BriefCam analytics and Arcules cloud video, with Arcules replacing Milestone Kite from January 2025.

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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