Summary Bullets:

• AI is driving up voice traffic while also making voice more vulnerable, so voice security needs urgent attention.

• The building blocks are in place, but solutions are fragmented. Voice security needs to be integrated on the carrier network level and backed by strong verification at the business.

Voice security is of paramount importance today. Advances in AI are affecting voice in two ways. First, AI is improving the voice experience as it becomes more interactive, which is expected to increase overall voice traffic. Second, AI can be used to bypass security barriers, significantly raising the threat level. The threat landscape varies depending on the call type, recipients, and network routing (such as international borders); this blog focuses on voice security within customer engagement (particularly contact centers), predominantly in the US.

Voice security in customer engagement is a multi-layered issue that must be viewed from the perspective of both incoming and outgoing calls:

• For incoming calls, the objective is to protect business systems from threats like telephony denial of service (TDoS), i.e., when business operations are flooded with fake calls to disrupt service or demand a ransom, or scammers posing as customers to access sensitive data.

• For outgoing calls, the goal is to ensure customers do not ignore crucial alerts, such as notifications of fraudulent bank activity or delivery confirmations.

The initial safety net for incoming calls must start on the carrier level, where threats like TDoS can be identified and mitigated at the network stage. A carrier helps determine a call’s legitimacy using Secure Telephony Identity Revisited / Signature-based Handling of Asserted information using toKENs (STIR/SHAKEN), a mandatory US government framework acting as a digital notary. The originating carrier attaches a digitally signed certification to each call:

• Full Attestation (Grade A): The gold standard; the carrier knows the caller and confirms they legitimately own the number.

• Partial Attestation (Grade B): The carrier knows the caller but cannot verify they own the number.

• Gateway Attestation (Grade C): The carrier simply passes the call along from an unverified, unknown source.

Relying solely on networks is not enough; spoofed calls can still slip through. Businesses require extra layers like call identification and authentication. Conversely, for outgoing calls, brands must ensure their outreach isn’t mistaken for spam. This is achieved by displaying a branding logo, verified number, and the reason for the call. Notably, ecosystem requirements are stringent—calls without the highest certification grade (Grade A) cannot utilize call branding.

A robust partner ecosystem in the US brings these pieces together:

• SecureLogix orchestrates the screening of incoming calls.

• TransUnion (via its Neustar division) operates a massive database of legitimate business numbers to match callers accurately.

• Pindrop addresses audio authenticity and caller verification once calls pass the carrier gateway and reach the business phone system.

• Hiya and First Orion provide branded calling for outgoing traffic, displaying logos and call reasons.

• TNS, a carrier network hub, operates the data highways that route cryptographic signatures for both initial screening and outbound branding.

While these building blocks are in place, the broader architecture needs attention. Point solutions remain fragmented and are generally sold as add-ons, leaving gaps and placing a costly, complex configuration burden on enterprises. Partner integration should ideally happen upstream on the carrier network routing level to seal the gap at the origin.

Furthermore, stronger verification is required at the business phone system layer, as AI voice cloning makes it easier than ever to impersonate customers. Implementing multi-factor authentication can reinforce this safety net. Finally, for outgoing calls, while cross-carrier interoperability has improved, branded calling can still experience fragmentation depending on the recipient’s mobile operating system and carrier ecosystem.