Yuri Borges Martins

18 · Brazil · Building open-source tools for content authenticity

I build software that proves things are real.

What I'm doing now

Building TrueShot, cryptographic photo verification for any Android device
Writing a paper on sensor-based screen recapture detection for IEEE WIFS 2026
Starting Computer Engineering in Granada, Spain (Fall 2026)
CTO at Amrntech, GovTech company building software for municipalities and state governments across Brazil

TrueShot, proving photos are real

An open-source Android camera that embeds cryptographic proof of authenticity in every photo. C2PA-inspired content provenance for the 3 billion devices that flagship-only solutions ignore.

Cryptography


Signing	ECDSA P-256 via hardware Keystore
Hashing	SHA-256 of JPEG bytes
Attestation	Validated against 3 Google Root CAs
Timestamps	RFC 3161 TSA + NTP anchoring
Identity	CAWG X.509 assertions

Novel research contributions


Screen detection	Sensor-based, not visual, no published precedent
Corroboration	Cross-device matching without communication
Sensors	14 physical sensors at capture time
Depth	DEPTH16 integration when hardware supports
Privacy	Zero analytics, zero cloud, zero tracking

Screen recapture detection results (Redmi Note 11S)

Scenario	Score	Flagged?
Normal photo (daylight)	20	No
Normal photo (dark room)	30	No
Screen capture (daylight)	70	Yes
Screen capture (dark room)	85	Yes

Minimum 40-point separation. Threshold: 60. Purely sensor-based, no ML, no image analysis.

Source Code · Web Verifier · Threat Model · Changelog

Tech

Pinned Loading

archive-book-liberator

Public

A powerful toolset to extract 'Borrow Only' books from Internet Archive and convert them into clean, local PDFs. Bypass timeouts and restrictions effortlessly.

JavaScript 10 3

TrueShot

Public

Cryptographic proof of photo authenticity for any Android device. ECDSA P-256 signed. SHA-256 hashed. 14-sensor fingerprinted.

HTML 15 1

GeezerVison

yuribm YuriTheCoder