YBM

Cryptographer · Engineer · Builder



Building open-source tools that prove things are real.

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01
About

I’m an 18-year-old developer from Brazil, CTO at a GovTech company serving municipalities across the country, and creator of open-source cryptographic tools. I’m writing a paper for IEEE WIFS 2026 on sensor-based screen recapture detection , a method with no published precedent. This fall, I’m moving to Granada, Spain to study Computer Engineering.

18Years old
CTOat Amrntech
IEEEWIFS 2026
2026Granada, Spain
OPEN SOURCECRYPTOGRAPHYANDROIDiOSGOVTECHIEEE WIFS 2026KOTLINREACT NATIVESPAIN 2026ECDSA P-256SHA-256CONTENT AUTHENTICITYOPEN SOURCECRYPTOGRAPHYANDROIDiOSGOVTECHIEEE WIFS 2026KOTLINREACT NATIVESPAIN 2026ECDSA P-256SHA-256CONTENT AUTHENTICITY
02
Projects
012026

TrueShot

Open-source Android camera that embeds cryptographic proof of authenticity in every photo. ECDSA P-256 signed, SHA-256 hashed, 14 sensors fingerprinted. C2PA-inspired content provenance for 3 billion devices.

KotlinJetpack ComposeCameraXECDSA P-256SHA-256
022025

Yorubs

Gamified mobile app to learn the Yorubá language. 11 learning modules, 19 exercise types, proprietary AI tutor, Sacred Library of 19 Orixás, and 358 authentic proverbs. Built with React Native and Expo.

React NativeExpo SDK 54TypeScriptProprietary AI
032025

Amrntech

GovTech platform serving municipalities and state governments across Brazil. Digital systems for health, education, security, infrastructure, social assistance, environment, civil defense, and transport.

JavaSpring BootReactCloudPostgreSQL
04
Journey
2024

Founded Amrntech

Started building GovTech solutions for Brazilian municipalities. Digital transformation for public services.

2025

Created Yorubs

Built a gamified Yoruba language learning app with proprietary AI tutor and Sacred Library.

2025

Became CTO at Amrntech

Leading engineering across health, education, security, and infrastructure systems for state governments.

2026

Launched TrueShot

Open-source cryptographic photo verification. ECDSA P-256 signing, 14-sensor fingerprinting, screen recapture detection.

2026

IEEE WIFS 2026 Paper

Writing a paper on sensor-based screen recapture detection. First non-visual approach with no published precedent.

2026

Moving to Granada, Spain

Starting Computer Engineering at the University of Granada. New chapter.

05
Research
IEEE WIFS 2026Novel

Sensor-Based Screen Recapture Detection

A non-visual approach to detecting photos of screens. Cross-correlates 10 physical sensor signals at capture time. Independent of image content and display technology. First method that scales with display improvements rather than degrading.

IEEE WIFS 2026Novel

Post-Hoc Cross-Device Corroboration

Verify that multiple photos from different devices depict the same real event , without any communication between devices. Uses barometric pressure, timestamps, GPS, and sensor coherence. Attack cost scales exponentially with each additional device.

Screen Recapture Detection Results

Redmi Note 11S · Purely sensor-based · No ML · Threshold: 60

Normal photo (daylight)
20Safe
Normal photo (dark room)
30Safe
Screen capture (daylight)
70Flagged
Screen capture (dark room)
85Flagged
06
Stack

Mobile

KotlinJetpack ComposeReact NativeExpo

Backend

JavaSpring BootNode.jsPostgreSQL

Frontend

ReactNext.jsTypeScriptTailwind CSS

Cryptography

ECDSA P-256SHA-256Android KeystoreX.509

DevOps & Tools

GitDockerGitHub ActionsVercel
OPEN SOURCECRYPTOGRAPHYANDROIDiOSGOVTECHIEEE WIFS 2026KOTLINREACT NATIVESPAIN 2026ECDSA P-256SHA-256CONTENT AUTHENTICITYOPEN SOURCECRYPTOGRAPHYANDROIDiOSGOVTECHIEEE WIFS 2026KOTLINREACT NATIVESPAIN 2026ECDSA P-256SHA-256CONTENT AUTHENTICITY
07
Contact

Open for collaborations, research opportunities, and interesting conversations.

© 2026 Yuri Borges Martins · Built with Next.js, GSAP & Three.js