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Cybersecurity · head to head

Sigstore vs Transmit Security

Sigstore logo

Sigstore

Cybersecurity

Free public signing and transparency infrastructure for open source artifacts

From
Free
Rated
-
Full reviewWebsite
Transmit Security logo

Transmit Security

Cybersecurity

Customer identity platform built around passwordless and fraud signals

From
On request
Rated
-
Full reviewWebsite

The short version

  • Only Sigstore has a free tier, so it costs nothing to try first.
  • Each has a real cost: Sigstore the security model depends on somebody watching the log. The documentation states that compromise of an identity provider or of Fulcio itself is detectable only if third parties monitor the transparency log, the monitoring tool is a community-tier rather than core project, and almost no consumer runs one.; Transmit Security pricing is not published, so it cannot be compared early against competitors that post per monthly active user rates, and the eventual quote often mixes per-user and per-transaction units.
  • They diverge on capability: Sigstore covers Fulcio, Transmit Security covers Passwordless authentication.
  • Prices and features above were last checked on 1 September 2026.

Where they differ

Only the attributes on which Sigstore and Transmit Security actually diverge.

Attributes where Sigstore and Transmit Security differ
AttributeSigstoreTransmit Security
Starting priceFreeOn request
Pricing modelOpen source, public instance free to usequote
Free tierYesNo
PlatformsWeb, Linux, macOS, Windows, Self-hostedWeb, 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 Sigstore

  • Fulcio
  • Rekor
  • Keyless signing
  • Multi-language clients
  • Timestamp authority
  • Neutral governance

Only in Transmit Security

  • Passwordless authentication
  • Detection and response
  • Identity verification
  • Orchestration
  • Account recovery
  • Bot and automation detection
  • Composable APIs

What people use each for

The jobs each tool is most often brought in to do.

Sigstore

  • Open source projects signing releases without running a certificate authoritynot Transmit Security
  • Organisations meeting a signed-artifact requirement without buying a signing productnot Transmit Security
  • Publishing provenance that a consumer can verify independently of younot Transmit Security
  • Self-hosting the same components where a public log is unacceptablenot Transmit Security

Transmit Security

  • A bank moving a consumer base off passwords to passkeys without losing customers at the migration stepnot Sigstore
  • An insurer whose account recovery flow is the main account takeover route and needs risk scoring inside itnot Sigstore
  • A retailer that wants bot detection at login rather than only at checkoutnot Sigstore
  • An organisation replacing an in-house customer login system that has become an unfunded engineering liabilitynot Sigstore

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Sigstore

  • The security model depends on somebody watching the log. The documentation states that compromise of an identity provider or of Fulcio itself is detectable only if third parties monitor the transparency log, the monitoring tool is a community-tier rather than core project, and almost no consumer runs one.
  • It is a 99.5 percent objective with no service level agreement, which permits several hours of downtime a month and offers no remedy. A pipeline that signs on every build has taken a hard dependency on a free service with no contract behind it.
  • Log scale is a live engineering problem rather than a theoretical one. The active shard holds billions of entries, the log has already been sharded twice, and sharding version 1 requires stopping traffic, which is why a replacement was built.
  • Ten-minute certificates make trust depend on log availability. Verifying an older signature relies on the log entry proving it was made inside that window, so a lost or unreachable entry can render a valid artifact unverifiable.
  • Migration debt is substantial and ongoing. Version 2 of the log is generally available but not the public default, the signing client has an announced breaking release ahead, some official clients lag the new log format, and a post-quantum migration is named as the next break after that.

Transmit Security

  • Pricing is not published, so it cannot be compared early against competitors that post per monthly active user rates, and the eventual quote often mixes per-user and per-transaction units.
  • Migrating a live consumer identity base is a high risk project, and credential migration constraints mean some users must re-register, which shows up as measurable churn.
  • The vendor is smaller than the identity incumbents, so the partner and systems integrator pool is thinner and staffing a large programme is harder.
  • Workforce identity is not the focus, so an organisation wanting one vendor for employees and customers will still run two platforms.
  • The fraud detection value depends on traffic volume feeding the models, so a smaller deployment gets less benefit from exactly the capability that justified choosing it over a plain identity provider.

Pricing, plan by plan

Sigstore

Free
  • Public good instanceFree
    • Free to everyone with no contract
    • 99.5 percent availability objective, not an agreement
    • 100KB cap per attestation upload
  • Self-hostedFree
    • Apache-2.0
    • Run your own Fulcio and Rekor
    • Rekor v2 available for self-hosters

Transmit Security

On request
  • Transmit Security Platform$undefined/year
    • Priced per monthly active user or per transaction by service
    • Services licensed individually or as a platform
    • Free developer tier for evaluation

Which should you pick?

Choose Sigstore if

  • You need fulcio.
  • You want to start without paying.
  • You work on Web, Linux, macOS, Windows, Self-hosted.
  • You also want rekor.
Sigstore review

Choose Transmit Security if

  • You need passwordless authentication.
  • You work on Web, iOS, Android.
  • You also want detection and response.
Transmit Security review

Questions people ask

Is Sigstore or Transmit Security better?
Neither clearly leads. Sigstore starts at Free and Transmit Security at On request, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Sigstore or Transmit Security?
Sigstore has a free tier; the other does not. Paid plans start at Free for Sigstore and On request for Transmit Security.
Does Sigstore or Transmit Security run on more platforms?
Sigstore runs on Web, Linux, macOS, Windows, Self-hosted. Transmit Security runs on Web, iOS, Android.
Can I use Sigstore for free?
Yes. Sigstore has a free tier, so you can try it without paying. Transmit Security starts at On request.
What is Sigstore best used for?
Sigstore is most often used for open source projects signing releases without running a certificate authority, organisations meeting a signed-artifact requirement without buying a signing product, publishing provenance that a consumer can verify independently of you, self-hosting the same components where a public log is unacceptable. Of those, open source projects signing releases without running a certificate authority and organisations meeting a signed-artifact requirement without buying a signing product are not what Transmit Security is typically brought in for.
What can Sigstore do that Transmit Security cannot?
Sigstore covers Fulcio, Rekor, Keyless signing, Multi-language clients. Transmit Security covers Passwordless authentication, Detection and response, Identity verification, Orchestration.

Answered from the vendors’ own pages

Sigstore: Is the public instance really free?

Yes, with no contract and no paid tier. That is also the weakness: a 99.5 percent objective with no agreement, no remedy and support through Slack.

Transmit Security: Do we have to replace our existing identity provider?

No. The services are composable, so detection and response or verification can be adopted alongside an existing provider such as Okta or Entra ID.

Sigstore: Has the public log moved to Rekor v2?

No. Version 2 reached general availability in October 2025 and self-hosters can use it, but the public instance still defaults to version 1 and the project has said it will for the foreseeable future.

Transmit Security: Is fraud detection an extra licence?

It is a separate service, but it is designed to run inside the authentication flow rather than as a bolted-on second vendor. Confirm which services are in your quote.

Sigstore: Does Sigstore make my dependencies safe?

No, and this is a category error worth avoiding. It tells you who published something. It has no knowledge of what the artifact contains or whether it is vulnerable.

Transmit Security: Is there a way to try it?

Yes, a free developer tier exists for evaluation, though production use is an enterprise agreement.

Sigstore: What are the rate limits?

Not published. Only the 100KB cap per attestation upload is documented, so do not design a high-volume pipeline around assumed throughput.

Sigstore: Should we self-host it?

If a public record of every signature is unacceptable, or if a free service with no agreement cannot sit in your build path, then yes. Otherwise the public instance is what most projects use.

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