Tutorial: What are One-Time Passcodes?
Typical authentication prompt from a website:
Typical passcode email or SMS message:
Definition: A one-time password is a temporary, single-use code that authenticates a user to a website or service.,
Why? Eliminate the risks of password reuse across multiple accounts (Multi-factor authentication).
Authenticators: Quick Review
Smartphone vs PC
Smartphones are vulnerable to damage, theft, or loss.
When logging in to a website using a browser on a laptop/desktop, it's inconvenient to have the authenticator on a separate device.
Windows/Mac/Linux?
Several Windows options, but only 2 for Linux.
The Linux applications don't meet John's use case:
- Seem aimed at "power users."
- UI is mobile-first and inscrutable on desktop.
EasyAuth Goals
- Run on Linux desktop.
- Simplify setup step - automatic QR code scanning without a phone.
- UI provides feedback for each action.
- Manage vault entries from the main screen.
- Free, open source, no advertisements, no tracking.
EasyAuth Demo
Video Tutorial (Ten Minutes)
TOTP Generation Details
TOTP Generation Code
Linux command line tool: oathtool --base32 --totp "SECRET" -d 6
Python library:
$ python3
Python 3.10.12 (main, Dec 8 2025, 13:56:28) \[GCC 13.3.0\] on linux
>>> import pyotp
>>> totp = pyotp.TOTP("sharedsecretkey")
>>> totp.now()
'069029'
>>> print ("Wait 30 seconds ...")
Wait 30 seconds ...
>>> totp.now()
'277434'
EasyAuth Website
This talk was presented at SLO Coders on May 18, 2026