Silent Network Authentication (SNA) — Zero-Friction Login
Verify user mobile devices invisibly via direct Claro, Vivo, and TIM data sessions. Maximize security with zero customer effort.
TL;DR — Summary
What is Silent Network Authentication (SNA)?
SNA is the cutting-edge standard in mobile identity security. Instead of routing text messages for manual entry, our API queries the cellular network to match the data connection to the phone number.
Runs silently in under 2 seconds, blocking phishing vectors and social engineering scams targeting SMS codes.
SNA Impact Metrics
SNA Key Capabilities
Frictionless Experience (No PINs)
Users register or login instantly without copying or typing security digits.
Social Engineering Protection
100% immune to SMS interception, fake caller IDs, or proxy attacks.
GSMA Open Gateway Alignment
Fully compliant with GSMA APIs run by Claro, Vivo, and TIM.
Step-by-Step Implementation
GSMA Open Gateway Access
Enable credentials linking your database platform straight to major Brazilian carrier nodes (Vivo, Claro, TIM).
Programmatic Network Queries
Trigger telemetry checks (like SIM Swap or Silent Network Authentication) invisibly via carrier tower routing.
Adaptive Fraud Decisions
Evaluate carrier feedback payloads on your server to request biometrics, selfie checks, or freeze transactions.
Industry-Specific Solutions
Banking & Fintech
SIM Swap checks during Pix transfers, invisible user authentication (SNA) via network cell towers, and loss prevention checks.
Varejo & E-commerce
Spam signup and bot prevention, loyalty points redemption protection, and secure coupon drops checks.
Healthcare & Clinics
Secure medical portal access verification, digital prescriptions auditing, and doctor authentication.
Logistics & Shipping
Driver geographical verification checks using carrier towers, secure drops check, and carrier network status.
Carrier-Grade Local Telecommunications
Unlike legacy global aggregators that suffer from network transit routing delays, BulkSMS provides direct channels with Vivo, Claro, and TIM.
We host our physical core architecture in São Paulo datacenters. This keeps message compliance fully aligned with Brazilian data security standards (LGPD) for all auditing purposes.
Our engineering operations desk provides qualified support in Portuguese 24/7/365, giving your product and dev teams immediate developer-to-developer assistance.
Open Gateway Partner
Direct channels with Vivo, Claro, TIM.
LGPD Sovereignty
São Paulo datacenters protecting user data.
24/7 Portuguese Support
Talk directly to local telecom developers.
Sub-Second Response
Very fast carrier-level telemetry queries.
What our customers say
about our services
"The SIM Swap API saved our fintech from catastrophic account takeover fraud. Indispensable telemetric check."
Paulo Mendes
São Paulo - SP
"We query the last SIM card change timestamp invisibly. Legitimate clients suffer zero onboarding friction."
Alessandra Negrini
Rio de Janeiro - RJ
"Silent Network Authentication (SNA) verifies identities invisibly via mobile carrier towers. Amazing technology."
Selton Mello
Paraná - PR
"GSMA Open Gateway integration approved directly with the tier-1 telcos (Vivo, Claro, TIM) with local support."
Letícia Sabatella
Minas Gerais - MG
"We eliminated account porting social engineering fraud by checking SIM changes during high-value Pix transfers."
Caco Ciocler
São Paulo - SP
"Sub-second API response time. Crucial to guarantee verify sweeps do not slow down our client sign-up funnel."
Cláudia Raia
São Paulo - SP
"Local log hosting in São Paulo and strict LGPD compliance. Paramount for our compliance committee audits."
Tarcísio Filho
Rio de Janeiro - RJ
"Bulk SMS's Network APIs leveled up our digital security. The best technical decision we made this year."
Glória Pires
Paraná - PR
Read more from our blog
SIM Swap Fraud in Brazil: Dynamic Prevention Guide & GSMA Network APIs in 2026
SIM Swap cost financial institutions over BRL 2.5 billion. Learn how open Network APIs and SIM Swap chequing prevent fraud in real time.
Silent Network Auth (SNA): The Next Generation of Passwordless Authentication in Brazil
Learn how Silent Network Auth (SNA) technology works, allowing companies to verify user identity without the friction of sending OTP codes.
Silent Network Authentication FAQ
Deploy Frictionless Identity Checks
Adopt SNA to secure user onboarding pipelines in Brazil.