Cybersecurity · head to head
Cosign vs ExpressVPN
Cosign
Cybersecurity
Signs and verifies container images and artifacts, with or without managing keys
- From
- Free
- Rated
- -
ExpressVPN
Cybersecurity
Consumer VPN registered in the British Virgin Islands, owned by Kape Technologies since 2021, with repeated third-party audits.
- From
- $6.67/month
- Rated
- -
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.; ExpressVPN ownership passed in 2021 to Kape Technologies, formerly Crossrider, whose earlier browser extension platform was widely used to distribute adware, and Kape also owns VPN review publications, so nominally independent rankings a buyer consults may originate inside the same corporate group.
- They diverge on capability: Cosign covers Keyless signing, ExpressVPN covers TrustedServer.
- Prices and features above were last checked on 31 August 2026.
Where they differ
Only the attributes on which Cosign and ExpressVPN actually diverge.
| Attribute | Cosign | ExpressVPN |
|---|---|---|
| Starting price | Free | $6.67/month |
| Pricing model | Open source, no licence fee | subscription |
| Free tier | Yes | No |
| Platforms | macOS, Linux, Windows, Docker | Web, Desktop, Mobile, Api |
| Founded | Unknown | 2009 |
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 ExpressVPN
- TrustedServer
- Lightway protocol
- Repeated external audits
- Network Lock
- Split tunnelling
- Aircove router
- Threat Manager
- Private DNS
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 ExpressVPN
- Attaching a signed bill of materials to a release so consumers can verify its provenancenot ExpressVPN
- Meeting a customer or regulatory requirement for signed artifactsnot ExpressVPN
- Verifying third-party images before they enter an internal registrynot ExpressVPN
ExpressVPN
- A buyer who wants the largest available body of published third-party audit evidence behind a no-logging claimnot Cosign
- Households wanting whole-network coverage through a router without configuring firmware by handnot Cosign
- Frequent travellers who need connections that survive switching between mobile data and hotel Wi-Fi without droppingnot Cosign
- Non-technical users who want the kill switch and DNS handled correctly by default rather than configurednot 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.
ExpressVPN
- Ownership passed in 2021 to Kape Technologies, formerly Crossrider, whose earlier browser extension platform was widely used to distribute adware, and Kape also owns VPN review publications, so nominally independent rankings a buyer consults may originate inside the same corporate group.
- In 2021 the company's then chief information officer was named in a United States Department of Justice deferred prosecution agreement over work for a foreign government's offensive cyber programme and remained in post, which is a governance fact that sits uncomfortably alongside a product sold entirely on trust.
- Audits are point-in-time engagements against an agreed scope, so they establish that specified servers and code matched the stated policy when examined, not that the infrastructure behaves the same way today or under different ownership.
- Several country locations are virtual, meaning the hardware physically sits elsewhere, and after India's 2022 directive requiring VPN providers to retain subscriber data ExpressVPN withdrew its Indian servers, so an Indian connection is routed through hardware in another country, which matters if you need genuine in-country routing.
- There is no port forwarding and no dedicated IP option, so seeding torrents, hosting a service behind the tunnel and any inbound connection do not work, and users who need those capabilities have to use a different provider.
Pricing, plan by plan
Cosign
Free- CosignFree
- Apache-2.0
- Public Sigstore infrastructure free to use
- No usage limits published
ExpressVPN
$6.67/month- 1 Month$12.95/month
- 8 devices
- 94 countries
- Unlimited bandwidth
- 12 Months$6.67/month
- All features
- 3 months free
- Best value
- 6 Months$9.99/month
- All features
- 30-day guarantee
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.
Choose ExpressVPN if
- You need trustedserver.
- You work on Web, Desktop, Mobile, Api.
- You also want lightway protocol.
Questions people ask
- Is Cosign or ExpressVPN better?
- Neither clearly leads. Cosign starts at Free and ExpressVPN at $6.67/month, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
- Which is cheaper, Cosign or ExpressVPN?
- Cosign has a free tier; the other does not. Paid plans start at Free for Cosign and $6.67/month for ExpressVPN.
- Does Cosign or ExpressVPN run on more platforms?
- Cosign runs on macOS, Linux, Windows, Docker. ExpressVPN runs on Web, Desktop, Mobile, Api.
- Can I use Cosign for free?
- Yes. Cosign has a free tier, so you can try it without paying. ExpressVPN starts at $6.67/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 ExpressVPN is typically brought in for.
- What can Cosign do that ExpressVPN cannot?
- Cosign covers Keyless signing, Key and KMS signing, Registry-native storage, In-toto attestations. ExpressVPN covers TrustedServer, Lightway protocol, Repeated external audits, Network Lock.
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.
ExpressVPN: Who owns ExpressVPN?
Kape Technologies, which acquired it in 2021. Kape was previously named Crossrider and also owns CyberGhost, Private Internet Access and Zenmate, along with the review sites vpnMentor and Wizcase.
Cosign: Is signing alone enough?
No. Verification is a command somebody runs. Without an admission controller enforcing it, an unsigned image still runs.
ExpressVPN: Is the British Virgin Islands jurisdiction actually useful?
It has no mandatory data retention law and is outside the Five, Nine and Fourteen Eyes arrangements, which is the reason it was chosen. It also means limited practical legal recourse for a subscriber, so the jurisdiction protects the company's ability to hold no data rather than protecting you against the company.
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.
ExpressVPN: Has the no-logs claim been audited?
Yes, repeatedly. PwC and KPMG have examined the no-logging claims and the TrustedServer architecture, and Cure53 has reviewed the applications, extension and protocol. The reports are published.
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.
ExpressVPN: Can I torrent with it?
Yes, peer-to-peer traffic is permitted on the network, but there is no port forwarding, so you can download but you cannot accept inbound connections and seeding performance suffers as a result.
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.
ExpressVPN: Does it work in China or similar networks?
Sometimes, using obfuscated connection modes, but no provider can guarantee this and availability changes without warning. Treat it as best effort and have a fallback.
Related pages
Other head to heads
- Cosign vs Sigstore
- Cosign vs Syft
- Cosign vs Chainguard
- Cosign vs HashiCorp Vault
- Cosign vs Infisical
- Cosign vs OWASP ZAP
- Cosign vs Wireshark
- Cosign vs Bitwarden
- Cosign vs Semgrep
- Cosign vs Trivy
- Cosign vs authentik
- Cosign vs Microsoft Intune
- Cosign vs Netwrix
- Cosign vs NordVPN
- Cosign vs Omada Identity
- Cosign vs Ory
- Cosign vs ProtonVPN
- Cosign vs Grype
- Cosign vs Avast One
- Cosign vs Norton 360
- Cosign vs 1Password
- Cosign vs Bitdefender Total Security
- Cosign vs LastPass
- Cosign vs IVPN
- Cosign vs Mullvad VPN
- Cosign vs Private Internet Access
- Cosign vs TunnelBear
- Cosign vs Windscribe
- Cosign vs Microsoft Defender
- Cosign vs Mimecast
- Cosign vs Motorola Vigilant
- Cosign vs Nessus
- Cosign vs NordPass
- Cosign vs Microsoft Sentinel
- ExpressVPN vs Sigstore
- ExpressVPN vs Syft
- ExpressVPN vs Chainguard
- ExpressVPN vs HashiCorp Vault
- ExpressVPN vs Infisical
- ExpressVPN vs OWASP ZAP
- ExpressVPN vs Wireshark
- ExpressVPN vs Bitwarden
- ExpressVPN vs Semgrep
- ExpressVPN vs Trivy
- ExpressVPN vs authentik
- ExpressVPN vs Microsoft Intune
- ExpressVPN vs Netwrix
- ExpressVPN vs NordVPN
- ExpressVPN vs Omada Identity
- ExpressVPN vs Ory
- ExpressVPN vs ProtonVPN
- ExpressVPN vs Grype
- ExpressVPN vs Avast One
- ExpressVPN vs Norton 360
- ExpressVPN vs 1Password
- ExpressVPN vs Bitdefender Total Security
- ExpressVPN vs LastPass
- ExpressVPN vs IVPN
- ExpressVPN vs Mullvad VPN
- ExpressVPN vs Private Internet Access
- ExpressVPN vs TunnelBear
- ExpressVPN vs Windscribe
- ExpressVPN vs Microsoft Defender
- ExpressVPN vs Mimecast
- ExpressVPN vs Motorola Vigilant
- ExpressVPN vs Nessus
- ExpressVPN vs NordPass
- ExpressVPN vs Microsoft Sentinel