What is an open gateway and why is it important for electronic signatures?

O open gateway It is an initiative that standardizes telecommunications network APIs to expose, with consent and security controls, capabilities useful to digital services, such as number verification and risk signals associated with the line.

In flows of electronic signatureThis helps reduce fraud and better validate who is signing and in what context, without relying solely on passwords or email. Therefore, the network becomes an extra layer of technical evidence: the system asks "is the number really associated with that device?" and "was there a suspicious SIM card swap?" and uses the answer as part of the decision-making engine.

Summary

• How the open gateway standardizes access to network functions via APIs with authentication and consent.
• Why signals like number verification and SIM swapping strengthen electronic signature flows.
• Good integration practices: data minimization, logs, and fallback strategies.
• Key performance indicators (KPIs) to track performance: fraud, conversion, completion time, and false positives.

Quick facts

• A decision reported by TJDFT on SIM swap This illustrates how security flaws in telephone lines can lead to legal repercussions and harm to consumers.
• An investigation released by PCDF on SIM swap It describes the use of multiple SIM cards and how the change of ownership can enable chain fraud.
• A record of Civil Police of Paraná It mentions "line hijacking" and temporary incommunicability as vectors for digital scams.

What is an open gateway?

Open gateway is a network-as-a-platform model: operators expose infrastructure capabilities (e.g., number validation, risk signaling, and chip-related events) through standardized APIs, with governance, authentication, and consent. The proposal gains traction when there is standardization among operators, because corporate integrations cease to be a puzzle of different contracts and endpoints.

An example of this pursuit of standardization is the CAMARA ecosystem, which organizes APIs into initiatives and subprojects, helping to maintain consistency in nomenclature, scopes, and security requirements. This foundation facilitates use in services such as onboarding, payments, and electronic signatures.

Why does API standardization change the game?

In practice, the main benefit is technical predictability: a standardized API tends to have the same contract across different networks, which reduces rework and the risk of specific dependencies.

The TM Forum, when discussing open APIs in the industry, cites more than 1.100.000 API downloads With over 60.000 developers using this as an indicator of scale and adoption, it helps contextualize the value of catalogs and standards. For legal and product teams, this means clearer governance: it's simpler to document the legal basis, map data flows, and audit integrations when API behavior is well-defined.

How does the open gateway connect to electronic signatures?

Electronic signing is a process based on trust: the organization needs to prove the integrity of the document and provide evidence of the signing act. Beyond what a platform records (logs, audit trail, and timestamp), network signals can provide an additional layer of contextual verification.

Instead of relying solely on email or OTP, the flow can use validations that reduce the risk of line hijacking or third-party account control. This aligns with best practices of... signature fraud, which often combine weak signals in chain attacks.

From consent to context: where do network signals come in?

In a typical design, the user accepts a consent form, and the backend calls operator APIs (directly or via an aggregator) to obtain binary responses or scores. The system doesn't need to see everything over the line; it can request only the minimum necessary for a decision, aligning with principles of... data minimization.

In environments that require stronger validations, this can complement steps of identity validationwithout unnecessarily increasing friction, because the checking happens in the background.

How it works at a high level

The process typically follows four blocks:

• authentication of the system consuming the API (keys, certificates, tokens);
• Collection of consent and recording of purpose;
• Calls to standardized APIs;
• Backend decision-making with rules and logs.

In the CAMARA ecosystem, for example, the Linux Foundation reports that the first meta-release brought together... 25 APIs across 13 subprojects, including features such as SIM Swap and Number Verification, which suggests catalog maturity and a focus on enterprise use cases.

Standardized APIs, but decisions remain with your system.

An important point: the open gateway does not replace the risk engine or the subscription policy. It provides input. The decision layer must combine what the platform already logs (IP, device, submission history, subscription attempt, trail) with API responses to approve, request extra verification, or block.

In more sensitive scenarios, it's possible to combine it with liveness or document validations, provided there is a clear justification and record of the legal basis and purpose in the workflow design.

Capability via API	What does he answer?	How does it help with signing?	Risk that mitigates
Number Verification	If the number is associated with the device/subscriber in a valid context.	Reduces approvals based solely on typed data.	Account created with a third party's number.
YES Swap	If there was a recent chip/line change (defined window)	Activates step-up (more evidence) when there is a sign of risk.	Takeover by "hijacking" of a phone line.
Device presence/range	Indication of device availability on the network.	It helps to validate the consistency of the act of signing.	Delegated signature without control

Use cases in subscription flows

In electronic signatures, the most common use cases involve verifying the number and detecting risk before completing the process. For example, a contract sent via WhatsApp or email may require that the number provided matches the device that opened the link, preventing someone from redirecting the flow to a third party.

Another frequent scenario is blocking subscriptions when there is a recent sign of a SIM card change, because this event is often present in scams that capture OTPs and take over accounts. In high-volume operations, these signs can reduce rework and disputes.

Number verification in portability and change of ownership scenarios.

When authentication uses a phone number, number portability and SIM card switching create points of attention. Anatel itself, when discussing anti-fraud procedures in number portability, mentions the requirement for SMS confirmation within [number of days]. 6hThis is a practical example of a control mechanism to reduce the risk of line "hijacking." In subscriptions, this logic becomes a risk rule: if a relevant event has recently occurred, the workflow may request additional evidence or wait for a safety window, depending on the level of exposure of the contract.

When to apply step-up instead of blocking

Blocking is simple, but it's not always the best approach. In sales, a hard block can derail conversions and create friction with the actual customer. A common strategy is step-up: maintain the flow, but request an extra verification when the network signal indicates risk.

This could be an enhanced authentication step, additional signatory validation, or a document check, as per policy. In terms of governance, this decision should be logged with the date, reason, and response received, supporting internal audits and potential legal challenges.

Flow stage	Recommended signal	Typical action	Expected effect
Before the subscription link	Number Verification	Allow submission only if consistent.	Fewer shipments to invalid numbers
Before completing the subscription	YES Swap	Step-up or rule-based blocking	Less fraud per takeover
Post-subscription	Logs and trail	Auditing and monitoring	Fewer disputes and less rework.

Best practices for secure and predictable integration.

The benefit of an open gateway becomes apparent when the integration is well-designed: requesting minimal data, logging decisions, and having a clear fallback process. Start by defining the purpose, legal basis, and log retention, aligning with policies. LGPD in digital signaturesNext, define windows and guarantees: SIM change within X days triggers step-up; number verification failure prevents completion. Finally, handle downtime: network and APIs can fluctuate, and the flow cannot break silently or approve everything due to lack of response.

Data minimization and observability

Avoid storing raw responses when a boolean resolves. If the API responds "yes/no" to number verification, store only the result, timestamp, correlation, and technical identifiers necessary for auditing.

In parallel, invest in observability: structured logs, latency metrics, and error rate per operator help to understand whether an increase in false positives is coming from the risk model or from external instability. A common basis is to use data encryption to protect tokens, keys, and audit trails.

Practice	How to apply	common mistakes	Result
fallback	If the API goes down, use a step-up or alternative route.	Approve without signal by default	Less risk of failures
Minimization	Keep only what is necessary (results and evidence).	Persisting with a complete payload without reason.	Reduced data exposure
Incident Handling	Logs with correlation, timestamps, and applied rules.	Log without decision context	Better traceability

Check out these related articles as well:

• The topic of validity and evidence appears in legal validity of electronic signature as a governance point for internal processes.
• The difference between subscription levels and forms is organized in electronic signature types to map requirements by contract type.
• The design of automation and integration can be understood in electronic signature API as a basis for system-oriented flows.

KPIs to measure real gains in the process.

To determine if network signals are helping, track before-and-after metrics, segmented by contract type and channel.

In the risk assessment, look at the confirmed fraud rate and dispute rate. In the funnel, track conversion by stage and time until subscription completion. In the experience assessment, monitor support tickets for authentication errors and abandonment.

The key point is balance: reducing fraud with an aggressive rule can increase false positives and lower ROI. Ideally, thresholds should be adjusted based on data and periodic reviews.

KPI	how to calculate	Practical reading	Common alert
Fraud rate	Confirmed fraud / transactions	If you fall, signs are there to help.	Underreporting of fraud
Signature conversion	Subscriptions completed / initiated	Shows the friction of the flow.	Fall after new rule
completion time	Average time to sign up	Indicates friction and rework.	Step-up without optimization
false positives	Improper blocks / blocks	Measures quality of control.	Long SIM swap window

Open gateway as a layer of trust for signatures.

When properly implemented, the open gateway adds technical network evidence to the signing process, reducing common loopholes in flows based solely on numbers and codes. The most efficient approach is iterative: define initial rules, instrument logs and KPIs, review false positives, and adjust guarantees based on risk profile.

The gains typically manifest as fewer disputes, less rework, and greater operational predictability. In the closing phase, a well-designed workflow also improves ROI by reducing cycle time and increasing completion rates.

In scenarios where an open gateway makes sense as a context reinforcement tool, it is possible to learn about... electronic signature solutions like ZapSign and evaluate how to integrate audit checks and trails into your process.

Frequently Asked Questions (FAQ)

Does the open gateway replace email or OTP authentication?

No. The open gateway provides network signals that complement authentication and audit trails. Instead of swapping one method for another, the most common use is to combine them: the flow continues with email or OTP, but uses number verification and risk signals to decide if a step-up is needed. This helps reduce fraud associated with account takeover and line "hijacking," without creating an extra visible step in every case.

Does Number Verification prove that the person owns the number?

Number verification typically validates consistency between a number and a device in a given context, which is different from proving absolute ownership. In electronic signatures, this signal is useful for reducing fraud through incorrectly typed numbers or numbers used by third parties. Even so, the final decision should consider other evidence, such as records of the signing process, document integrity, and, when necessary, additional validations from the signatory.

How does SIM swapping factor into the risk of electronic signatures?

SIM swap indicates a recent chip change or alteration associated with the line, an event that appears in many scams because it allows for the interception of messages and codes. In electronic signatures, this signal can trigger a step-up or blocking according to the policy and type of contract. The central point is to calibrate the window and action: strict rules reduce fraud, but can increase false positives. Therefore, the recommendation is to monitor metrics and adjust thresholds based on real funnel data.

What data should be saved for auditing purposes when using an open gateway?

Ideally, log only the minimum necessary information to document the decision: the result of the call (e.g., approved or rejected), timestamp, technical correlation identifiers, the rule applied, and the policy version. Avoid persisting the entire payload if it is not necessary. In addition to reducing exposure, this facilitates compliance with retention and disposal procedures. Structured logs and monitoring of latency and failures also help distinguish integration errors from attempted fraud.

How can we prevent integration from increasing friction and driving down conversions?

A common strategy is to use network signals silently and trigger step-up only when there is risk. Instead of imposing extra verification for everyone, the flow keeps the experience simple in most cases and reinforces evidence only in exceptions. To ensure balance, track conversion by step, completion time, and false positives. If the rate of improper blocking increases, adjust the risk window and refine rules by contract type and subscription channel.