YubiKeys are handy little USB tokens that allow for hardware-based cryptography, which are becoming ever more prevalent. They provide support for a great variety of cryptographic protocols and standards, and offer several modes of operations. While this makes them very versatile, it can also be somewhat confusing, especially when you are only getting in touch with them for the first time. This talk is an introduction to YubiKeys. It will explain what multifactor authentication is about, what kind of problems the YubiKey is addressing, and how the different modes of operation can be used to improve computer security. In this talk two new emerging authentication standards will also be touched upon, namely WebAuthn and FIDO2. These are related to the YubiKey and in combination will make authentication throughout the Internet substantially more secure. More importantly, however, it is very easy to use - even by non-technical people! A live demonstration will show you how a typical workflow looks like. Some advice and good practice, along with a Q&A session will conclude the talk. Recently some effort has been put into packaging and updating the software stack for YubiKeys within openSUSE, so that everything (including the latest generation of YubiKeys) are supported out-of-the box. For this talk no prior knowledge about the topic is required and/or expected. Any cryptographic concepts that are needed for explanation will be introduced on a high-level during the talk. Having basic cryptographic knowledge will definitely make it easier to follow along on some details, though.