Hey r/VeraCrypt,

I built an Android app called OTG Master that lets you mount VeraCrypt-encrypted USB drives directly on your phone or tablet over USB OTG — no root, no PC, no internet connection ever required.

A bit of background: this started as a personal tool. I carry encrypted drives for work and got tired of needing a laptop just to access them on the go. I wrote OTG Master for myself, used it quietly for a while, and eventually thought — if it's useful to me, it's probably useful to others here too. So I cleaned it up, added proper features, and decided to ship it.

What it does

- Unlocks and mounts VeraCrypt volumes directly from a USB drive plugged into your Android device (USB OTG)

- Supports FAT32 and exFAT filesystems inside the VeraCrypt container, with full read/write

- Supports AES, Twofish, Serpent ciphers and SHA-512, Whirlpool, SHA-256 hash algorithms

- Supports PIM and keyfiles

- Auto Mount: remembers known drives and prompts you with biometric authentication on reconnect — no need to re-enter your password every time

- USB hub support: plug in multiple encrypted drives at once and get a single biometric prompt for all of them

- Detects whole-device volumes as well as partition-based containers

Privacy and security

- Zero internet access — the app has no network permission whatsoever. It cannot phone home, send telemetry, or leak anything. You can verify this yourself in the source code or by checking the app's permissions on your device.

- Open source — full source on GitHub

- Free, no ads, no trackers, no subscriptions — I built this for myself first; monetisation was never the goal.

- Credentials are stored in Android's encrypted keystore, never on disk in plaintext.

How to join the beta

Join the OTG Master Beta Testers Google Group and then opt in via the Play Store:

- Join on Android

- Join on the web

Please don't use drives containing data you can't afford to lose during initial testing. The core crypto is well-tested but filesystem write paths on unusual configurations may surface bugs I haven't hit yet. Test with a dedicated drive first. Once you're comfortable with the behaviour, your call.

Any bugs, crashes, or unexpected behaviour — please open an issue on GitHub or drop a comment here. Both are watched.