Getting to Grips with YubiKeys


Do you need one? I'd suggest you get two, probably better than dealing with identity theft or phishing.

Are they easy to use? Yes, incredibly easy for services that support the simple button press / NFC touch auth (U2F authentication) and allow you to register multiple keys like Facebook and Gmail, for example. There are other auth methods available, but they do have additional steps.

How do they work? They fulfil the 'something you have' criteria of keeping your accounts safe, in a secure enough way that it is likely near-impossible for somebody to impersonate you.

Which one should I get? Two YubiKey 5s with NFC and USB-C (if you have USB-C laptops / computers and phone that supports NFC which most Android and iPhone models now do), otherwise possibly the regular USB/NFC model.

Are they worth the money? I think you'd have to ask yourself that after somebody hacked your accounts, because they are quite expensive, but you will probably avoid getting all your online identity hacked.

My Motivation

Scared that if I lose access to the Google Authenticator App, I risk losing access to several of my accounts, I wanted a better solution. With Google Authenticator if I brick my phone (which I have done a few times before), the codes it provides are lost for good. I decided it was time to take the plunge and get a Yubikey.

Or rather two YubiKeys...

The first thing to learn about YubiKeys (and other security keys) is that you really need at least 2. You don't want to have only one that provides access to all your accounts in case you break or lose it. There is just too much risk of being locked out of your own accounts (which could be a positive if the risk of somebody with physical access to your stuff gaining access to your key was greater than losing your own access – i.e. probably very few of us). Of course, setting up two keys adds a major constraint because you need to have them both physically present when you register them as a 2FA device, and then you need to be able to get the hot spare when you lose / break the other. Also it is worth considering where to keep the second key, as each option has significant trade-offs.

The above examples are just a playful brainstorm, but after the California Wildfires, many people have questioned their digital backup plans immensely as some people have literally had their house, including safes and even local banks, all burn to the ground.

Luckily (for most people), the majority of services will be able to return access to you, resetting your 2FA – upon proving your identity somehow. This account reset/restore option is often just your email address, so it is important that you ensure your main or backup email accounts are well-secured, and often you can have additional second factors like mobile phone numbers. It is probably worth using this, in spite of the lower security of SMS two-factor.

Main Types of Auth


This is excellent. You get all the benefits of the security key, with a pretty seamless user experience baked into most browsers, phones and computers. You just touch or insert and tap the key. Often you can easily register multiple hardware keys to your account, so setting up your backup key(s) can be done easily.


One time pass-codes are the most common form of secure 2FA. Many services support this, and there is a Yubico Authenticator app (and desktop version) that will enable you to store them on your key, and access them by inserting via USB or touching the key to phone. The biggest hassle is that for a backup you really need to scan the 2FA setup barcode twice, so you can add the code to your backup key as well as your main key. It is easy to do this with the app, but you have to remember to do it before moving to the next step, as they will never show you that code again. An alternative is to store that setup code in a password manager, but that will (to some extent) weaken your security, as if a hacker gets access to your password manager, they will then have both your 2FA and account passwords – and so it at least partially reduces the security you get from 'something you have' not being online.

Local Machine

While more for advanced users / secure workplaces, you can also set up your computer to require your key to unlock, access the admin etc. I must confess I've only done it on Linux, and it was as simple as installing a couple of packages and editing a couple of lines of certain authentication management files (with instructions from a guide Yubico provided online). As with all the above, but with even greater emphasis: make sure to have a backup key added, as losing access to your computer can be an extremely annoying occurrence, that might result in your having to re-install the operating system from scratch.

If you enable this, you are much less exposed to people in your office / house being able to access your machine while you briefly step away, and even if they have watched you type your password, or recorded it with a keylogger – they need the key and the password, so it at least makes it much more difficult to obtain both parts required to log in to your machine.

A big plus is that you can also mitigate the action movie risk scenario that iris and fingerprint auth can be accessed by cutting out/off those body parts. At least handing over your YubiKey is less painful.

Remote Machine (SSH)

If you don't know what this is, it is probably not useful to you, but it is possible to use a YubiKey as an OpenPGP Smartcard and generate PGP keys inside the key (so the master key can never* leak), or you can put your own subkeys on the security key, and then you can use GPG-Agent to enable using it for SSH. The benefit of this is that if you put the same PGP keys on both your keys, they can both be used for SSH access (although you need to run a command to reset the agent to switch between keys on same machine), but now you have a hot SSH spare at least, so you can still access your servers.

You need to unlock the key with a pin, so it is not trivial somebody to steal the key and gain SSH access. and there are only 3 attempts. You can unlock with an admin pin – but if you fail that 3 times, you have no choice but to fully reset OpenPGP on the card. Going even more technical, if you have an additional SSH hop, it is worth mentioning that SSH agent-forwarding is complex, with various security risks, so I won't cover it here – but it is possible to achieve.

This should now mean that you can set up ssh access to your services on any machine without having to transfer your private key file. You just need to set-up gpg-agent.

I'll go more into my struggles with the PGP stuff in an article about encryption, email and YubiKeys soon. It is certainly still .


I do think that the benefits of YubiKeys outweigh the hassle, and are a good (albeit expensive) way to reduce your surface area for identity theft and protect your accounts. They are complementary to a good password manager (which if you don't have, I'd recommend setting up first) – as what you really want to prevent is one account hack leading to multiple compromised accounts, so using the same password anywhere is ill-advised, and the addition of a 2FA will then further reduce the risks of mass-compromise.

Servers can still be hacked, so security keys don't actually increase the trust you should place in websites and apps that you give your data to, however they are a great defence against increasingly common and sophisticated phishing attacks, and as cyber criminals get more advanced, this is a strong step in limiting the ways that they are able to target you. I like to compare this sort of security with bike locks. You cannot buy a perfect (yet practical) bike lock – but you can have a better lock than other bikes on the street. Most criminals are going for the easiest wins, and simply by making yourself a more difficult target, you greatly reduce the number of people who would/could bother.

Finally, the less technical the person – the greater the risk of phishing and poor passwords – so if you can help someone who you think would likely click on malicious email links set up and use 2FA for the most crucial accounts, you probably should. U2F is genuinely quite easy to use, and simply requires tapping the key against your phone, or shoving it in the USB slot and touching it.

* hopefully