If you’ve recently purchased voice services, completed Know Your Customer (KYC) documentation, or heard your telecommunications provider mention STIR/SHAKEN compliance, you may have encountered terms like STI-GA, STI-PA, and STI-CA. While these acronyms sound highly technical, they play a critical role in protecting businesses and consumers from caller ID spoofing, robocalls, and voice fraud.

Let’s break down what these organizations do, why they exist, and how they ultimately benefit the end users of telecommunications services.

STIR/SHAKEN is a framework developed by the telecommunications industry and mandated by the FCC to help verify that a phone call is actually coming from the party displayed on the caller ID.

The acronym combines two industry standards:

• STIR – Secure Telephone Identity Revisited
• SHAKEN – Signature-based Handling of Asserted Information Using toKENs

Together, STIR/SHAKEN allows voice service providers to digitally sign calls and verify the identity of callers as calls travel across telecommunications networks.

Think of it as a digital certificate system for phone calls, similar to the security certificates that help verify websites on the internet.

For years, scammers exploited weaknesses in the public telephone network by falsifying caller ID information, a practice known as caller ID spoofing.

Fraudsters could make calls appear to come from:

• Banks
• Government agencies
• Healthcare providers
• Local businesses
• Even your own phone number

This led to:

• Increased robocalls
• Consumer fraud
• Loss of trust in phone communications
• Lower answer rates for legitimate businesses

STIR/SHAKEN was designed to restore trust in voice communications by providing a method to verify caller identity before a call reaches its destination.

The Secure Telephone Identity Governance Authority (STI-GA) serves as the governing body of the STIR/SHAKEN ecosystem.

Its primary responsibilities include:

• Establishing policies and governance rules
• Defining who can participate in the STIR/SHAKEN framework
• Overseeing trusted entities within the ecosystem
• Maintaining the integrity of the caller authentication process

Think of STI-GA as the organization’s board of directors responsible for creating the rules and ensuring the entire system operates fairly and securely.

Without STI-GA, there would be no centralized governance structure to ensure consistency and trust across participating telecommunications providers.

The Secure Telephone Identity Policy Administrator (STI-PA) acts as the gatekeeper for telecommunications providers seeking participation in STIR/SHAKEN.

The STI-PA is responsible for:

• Verifying service provider eligibility
• Confirming FCC and regulatory compliance
• Managing access to authentication credentials
• Maintaining trusted provider records

Before a telecommunications carrier can digitally sign calls, it must be approved through the STI-PA process.

This verification helps prevent bad actors from obtaining the credentials needed to falsely authenticate fraudulent calls.

The Secure Telephone Identity Certification Authority (STI-CA) issues the digital certificates used within the STIR/SHAKEN framework.

Its responsibilities include:

• Issuing secure digital certificates
• Validating provider identities
• Managing certificate lifecycles
• Revoking certificates when necessary

These certificates function much like SSL certificates used by secure websites.

When a call is placed, the originating provider uses its STI-CA-issued certificate to digitally sign the call. The receiving provider can then validate the signature and determine whether the caller identity can be trusted.

A simplified example looks like this:

1. A business places a call.
2. The originating carrier verifies the business’s right to use the phone number.
3. The carrier digitally signs the call using its STIR/SHAKEN certificate.
4. The call traverses the telecommunications network.
5. The receiving carrier verifies the digital signature.
6. The call is delivered with an indication of its authentication status.

This entire process occurs in milliseconds and is invisible to the caller and recipient.

A key component of STIR/SHAKEN is call attestation.  Attestation is a confidence level assigned by the originating service provider.

Full Attestation (A-Level)

The provider knows:

• The customer placing the call
• The customer is authorized to use the calling number

This represents the highest level of trust.

Partial Attestation (B-Level)

The provider knows:

• The customer placing the call
• But cannot fully verify ownership of the calling number

Gateway Attestation (C-Level)

The provider received the call from another network and has limited information about the original caller.

Analytics engines and terminating carriers often consider these attestation levels when determining how to treat incoming calls.

Legitimate businesses gain several important advantages:

• Improved Call Answer Rates- Verified and properly authenticated calls are more likely to reach customers without being flagged as suspicious.
• Better Caller Reputation- Businesses that maintain compliant telecommunications practices can improve their overall calling reputation.
• Reduced Fraud Risk- Authentication makes it significantly harder for scammers to impersonate legitimate organizations.
• Increased Consumer Trust- Customers are more likely to answer calls when they have confidence that caller identities are legitimate.

Consumers experience several benefits from the STIR/SHAKEN framework:

• Fewer Spoofed Calls- Scammers face greater difficulty disguising their identities.
• Better Fraud Protection- Authentication helps carriers identify potentially suspicious calls.
• Improved Caller Transparency- Consumers gain greater confidence that displayed caller IDs are accurate.
• More Trustworthy Communications- Phone calls become a more reliable communication channel as spoofing and fraudulent activity are reduced.

In recent years, regulators have increasingly focused on Know Your Customer (KYC) requirements for voice providers.

Telecommunications carriers are now expected to verify:

• Business identity
• Tax identification information
• Physical address
• Authorized representatives
• Intended use of services

These verification efforts help ensure that only legitimate organizations obtain phone numbers and voice services, strengthening the effectiveness of STIR/SHAKEN.

STI-GA, STI-PA, STI-CA, and the STIR/SHAKEN framework work together to create a trusted telecommunications ecosystem. While most businesses and consumers never see these systems operating behind the scenes, they play a vital role in combating caller ID spoofing, reducing robocalls, and restoring confidence in voice communications.

As regulatory requirements continue to evolve, organizations that maintain accurate customer records, comply with KYC requirements, and work with trusted telecommunications providers will be best positioned to ensure their calls are delivered, authenticated, and trusted by the people they are trying to reach.

About ACC Telecom

ACC Telecom is a leading provider of business telecommunications solutions, helping organizations across the United States improve communication, collaboration, and customer engagement through advanced voice, unified communications, and network services. As a fully compliant participant in the STIR/SHAKEN ecosystem, ACC Telecom maintains the certifications, credentials, and industry partnerships necessary to support secure and trusted voice communications. Our services are backed by STIR/SHAKEN authentication, participation within the STI-GA, STI-PA, and STI-CA framework, and support for A-Level (Full) Attestation, providing the highest level of caller identity verification available. By combining regulatory compliance, robust Know Your Customer (KYC) procedures, and industry-leading telecommunications expertise, ACC Telecom helps businesses protect their brand reputation, improve call answer rates, and ensure their communications are trusted by customers, partners, and stakeholders. Learn more about how ACC Telecom can help your organization navigate today’s evolving telecommunications landscape at ACC Telecom.