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Cybersecurity · head to head

Cosign vs Mullvad VPN

Cosign logo

Cosign

Cybersecurity

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

From
Free
Rated
-
Full reviewWebsite
M

Mullvad VPN

Cybersecurity

Privacy-first VPN with one flat price and no email required to sign up

From
$5/month
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.; Mullvad VPN offers no free trial or free tier, unlike several consumer VPN competitors.
  • They diverge on capability: Cosign covers Keyless signing, Mullvad VPN covers Flat single pricing.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Cosign and Mullvad VPN actually diverge.

Attributes where Cosign and Mullvad VPN differ
AttributeCosignMullvad VPN
Starting priceFree$5/month
Pricing modelOpen source, no licence feesubscription
Free tierYesNo
PlatformsmacOS, Linux, Windows, Dockerwindows, mac, linux, ios, android
FoundedUnknown2009

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 Mullvad VPN

  • Flat single pricing
  • Account-number signup
  • Cash and crypto payments
  • WireGuard support
  • Independent audits

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

Mullvad VPN

  • Paying for a VPN anonymously with cash or cryptocurrencynot Cosign
  • Avoiding tiered upsells with a single flat-rate plannot Cosign
  • Signing up without providing an email addressnot Cosign
  • Verifying a provider's privacy claims via independent auditsnot 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.

Mullvad VPN

  • Offers no free trial or free tier, unlike several consumer VPN competitors.
  • Lacks a bundled tiered structure, so there is no cheaper limited plan for occasional users.
  • Server network and streaming-unblocking performance is smaller than large mainstream VPN providers.
  • No annual discount, meaning long-term subscribers pay the same monthly rate as short-term users.

Pricing, plan by plan

Cosign

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

Mullvad VPN

$5/month
  • Mullvad VPN$5/month
    • Flat rate regardless of subscription length
    • 5 simultaneous devices
    • No email required

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 Mullvad VPN if

  • You need flat single pricing.
  • You work on windows, mac, linux, ios, android.
  • You also want account-number signup.
Mullvad VPN review

Questions people ask

Is Cosign or Mullvad VPN better?
Neither clearly leads. Cosign starts at Free and Mullvad VPN at $5/month, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Cosign or Mullvad VPN?
Cosign has a free tier; the other does not. Paid plans start at Free for Cosign and $5/month for Mullvad VPN.
Does Cosign or Mullvad VPN run on more platforms?
Cosign runs on macOS, Linux, Windows, Docker. Mullvad VPN runs on windows, mac, linux, ios, android.
Can I use Cosign for free?
Yes. Cosign has a free tier, so you can try it without paying. Mullvad VPN starts at $5/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 Mullvad VPN is typically brought in for.
What can Cosign do that Mullvad VPN cannot?
Cosign covers Keyless signing, Key and KMS signing, Registry-native storage, In-toto attestations. Mullvad VPN covers Flat single pricing, Account-number signup, Cash and crypto payments, WireGuard 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.

Cosign: Is signing alone enough?

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

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.

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