Answer your phone with confidence

V-Captcha is a new network-based service that integrates with mobile carrier networks to prevent unwanted calls and thwart call spoofing, even from unknown numbers. V-Captcha enables network operators to offer a highly effective nuisance call protection service to grow ARPU while significantly increasing subscriber loyalty.

Block unwanted callers, not numbers

V-Captcha prompts unknown callers or suspected scam callers to respond to a random question, such as “How many sides does a triangle have?” This interaction, similar to a CAPTCHA question on web sites, interferes with automated robocall systems, and the subscriber’s phone never rings.

Protection for today and tomorrow

V-Captcha succeeds, even when spammers use sophisticated tactics like local exchange spoofing, silent calling and churn and burn, or rotating through originating phone numbers in rapid succession.

Invisible to friends, families & colleagues Levels

When subscribers opt in to this service, their existing phone contacts are whitelisted automatically. Any entries in the user’s address book are routed through unimpeded. New callers hear a friendly greeting and can be automatically added to the whitelist when the challenge question is answered correctly.


V-Captcha works with any mobile carrier’s network as a fully managed service. Carriers perform a simple integration of the RealNetworks® Smart Call Manager (SCM) platform. Subscribers need only install an easy-to-use mobile app, with no further configuration necessary.

Subscribers control the experience

Subscribers can adjust question difficulty, and toggle protection on and off. They can also choose how to handle failed calls, by either sending them directly to voicemail, sending an SMS notification to their phone, or dropping the call altogether.

Private and Secure

Subscriber contact data is private, not shared and stored securely.

Have Questions?

Learn more about V-Captcha. Email bizdev@realnetworks.com.