Trillbit

Trillbit builds a data-over-sound proximity authentication protocol that encodes authentication data into inaudible or near-inaudible acoustic signals, allowing any device with a standard microphone and speaker — including legacy industrial hardware and smart speakers, not just modern smartphones — to perform contactless authentication without Bluetooth pairing, NFC hardware, or typed codes. The company frames sound as a physically bounded channel: because acoustic signals do not travel outside a room or a defined physical space the way Wi-Fi or Bluetooth signals can, using sound as a first- or second-factor credential adds a genuine proximity constraint that RF-based methods don’t inherently provide.

Founded in 2016 by IIT Kharagpur and ISB alumni Bhaskar Deo, Shashikant Burnwal, and Mrigesh Parashar, Trillbit is a Techstars alumnus and has raised a $1.5 million seed round from Refex Capital and Good Growth Capital. The company positions its technology for device provisioning, user authentication, physical access control, and check-in/check-out use cases layered with standard encryption (AES, RSA, TOTP) rather than replacing cryptographic authentication outright.

Trillbit is a small, early-stage company and its core claims — reliability across lighting, orientation, and movement conditions that challenge QR/NFC alternatives — are largely vendor-described rather than independently benchmarked. The underlying idea (acoustic side-channels for proximity-bounded authentication) has prior academic grounding, but real-world adoption at scale outside of Trillbit’s own case studies has not been independently documented.