The Yubico YubiKey 5C is a hardware authentication device that provides strong two-factor authentication for securing online accounts and services. This compact USB-C security key measures 44 mm in length, 12.5 mm in width, and 3.3 mm in thickness, weighing only 4.5 grams for easy portability. It supports multiple authentication protocols including FIDO2, FIDO U2F, YubiOTP, OATH-HOTP, OATH-TOTP, OpenPGP, and smart card functionality (PIV). The device features a capacitive touch sensor that activates with a simple tap and requires no batteries or external power source. Built with a robust polycarbonate casing, the YubiKey 5C is designed for everyday use and is resistant to water, dust, and mechanical impacts. It works with thousands of online services such as Google, Facebook, Microsoft, GitHub, and password managers. The security key supports USB-C connections for modern computers, laptops, and mobile devices with appropriate adapters. Setup is straightforward with platform-specific instructions provided by service providers. This authentication device protects against phishing attacks and unauthorized account access by requiring physical possession of the key for login verification. It is compatible with Windows, macOS, Linux, Chrome OS, Android, and iOS systems. The YubiKey 5C maintains user privacy by storing login credentials locally on the device rather than in the cloud. It is a successor to earlier YubiKey versions with enhanced protocol support and a USB-C connector for contemporary computing environments.