Questions tagged [yubikey]

YubiKey is an USB authentication key developed by Yubico.

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145 views

Should I use the same OpenPGP keys in certificates used to provision the YubiKey PIV slots?

I know PIV and OpenPGP are separate standards and independent applications in the YubiKey, but for newcomers like me they look very similar with their signing, encryption and authentication keys, use ...
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219 views

yubikey creating different ssh public key having same GPG

I have 2 yubikeys and both are having the same GPG master key besides 3 subkeys for encrypting, signing and authentication, I can encrypt/decrypt and everything regarding gpg seems to be working fine, ...
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2answers
343 views

Security benefit of hardware backed host keys for OpenSSH

There was recently a "two for the price of one" deal on the Yubikey 4 and now I have too many of them. This got me thinking about things to do with them, more or less useful. Of course I already use ...
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1answer
1k views

How does the YubiKey Validation Server work from an encryption perspective?

Many YubiKey servers rely on the free cloud hosted authentication that comes with the product, but I'm interested in keeping all cryptographic material in my control. For that reason I am looking at ...
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1answer
1k views

What does the “configuration protection” mode do on Yubikeys?

I can't seem to find any documentation on what these options do: Does this somehow offer more protection to your secret key? That is all I can think it would do.
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2answers
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How do I back up YubiKey-backed TOTP authentication?

I bought a YubiKey 5 NFC this week and have started using 2FA and U2F where I can but am deathly allergic to the idea of losing access. For backing up U2F access I'm going to buy a second U2F token (...
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2answers
308 views

Does YubiKey with LastPass influence encryption?

I am using LastPass together with a YubiKey Neo. If someone got ahold of my master password (e.g. keylogger), and a copy of my encrypted password vault, would they be able to decrypt it? Or does the ...
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1answer
118 views

Can a provider allowing 2FA with a Yubikey identify me if I use the same key for different accounts?

I was wondering if someone providing a service can identify me (other than by IP, browser fingerprinting etc.) purely based on the code generated by the Yubikey when I touch it, if I use the same ...
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1answer
3k views

Windows GnuPG - GPG - Smart Card Status - Not Detecting Yubikey

I have a Yubikey 4. On a Windows 7 64 bit machine I installed Gpg4Win which includes GnugPG. I was able to successfully import public keys. I plugged in the Yubikey 4 and Windows correctly ...
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2answers
589 views

Encryption using multiple Yubikeys, any of which can unlock

I was hoping to use my Yubikey for file encryption, but also wanted to have a backup Yubikey work to unlock the file. From a conceptual point of view, I know it is possible since, even as is, I ...
3
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1answer
596 views

Is it possible to have an RSA authentication subkey with a DSA master key?

My key setup is as follows: sec dsa3072/CA72E53A created: 2013-05-12 expires: never usage: SCA trust: ultimate validity: ultimate The following key was revoked on 2016-01-13 ...
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1answer
525 views

In the context of FIDO U2F, when is a new ephemeral key reused, or cached?

I'm reading this paper from Yubico on Universal Second Factor and OpenID Connect and see the description about ephemeral keys I'm confused on when a ephemeral key is used, and under what conditions ...
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53 views

What exactly is the Management Key on a yubikey?

The yubico documentation mentions that a Management Key can be set manually, or it can be inferred in the SoC when setting a PIN for the first time. What exactly is that management key and how does ...
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77 views

Does the output of --export-ssh-key change with different subkeys?

I use gpg --export-ssh-key to generate a public RSA key I can add to my authorized_keys file for the purposes of accessing my server via SSH. I have two Yubikeys (Yubikey 5 NFC) with the same subkeys ...
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868 views

How do security properties of Trezor's FIDO U2F differ from Yubikey?

Aside from being a bitcoin wallet, the Trezor supports FIDO U2F and seems to offer some unique benefits over a Yubikey: The keys are always generated on the device and never rely on the manufacturer ...
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4answers
541 views

Does a two-factor authentication dongle (OTP) which is always inserted in MacBook add a security benefit?

I think to get a Yubikey and read that Keepass with OTP makes no sense No. Security remains the same + extra cognitive overhead. I try to store all data local and use seldom cloud based services. If ...
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3answers
1k views

Vulnerabilities despite FIDO U2F?

FIDO U2F seems much more secure than one-time-passwords (OTP), especially TOTP, because of the challenge-response architecture. In what ways is a U2F user still vulnerable? I presume if a user's ...
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1answer
1k views

Can I generate and store keys on my Yubico?

Its a simple question but there's no answer in the Yubico's website When I recive a Yubico (from the Yubico 4 series), I know I can sign code, for example. But how is the key inside it generated? Is ...
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1answer
207 views

gpg ignores passphrase on my key stored on yubikey 5 nfc

I just set-up my yubikey 5 nfc with 3 seperate subkeys (S, E, A). While encrypting and decrypting works fine (self-tested), I'm questioning the fact that gpg only ever asks me for the yubikey's pgp ...
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1answer
83 views

Does password strength matter when using a YubiKey? [duplicate]

I'm considering buying a YubiKey. I already use a password manager which can generate strong passwords, but I wonder if there's even a point with the YubiKey. I guess it just makes one extra step......
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1answer
1k views

Why do I get a warning when specifying the recipient for signing a document?

I just got a Yubikey 4 and I generate the key with gpg2 --card-edit and now I have this: $ gpg2 --list-key /home/lilas/.gnupg/pubring.kbx ------------------------------ pub rsa2048/EA3829E3 2016-11-...
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2answers
771 views

Why is the U2F secret key on yubikeys is not programmable, and how to get a universal backup token?

I'm trying to figure the best strategy for having a backup U2F token. Ideally, I want to have two identical tokens; obviously I'll have the primary one easily accessible (say, on my keyring), but the ...
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2answers
270 views

How does concatenating a user password and a YubiKey OTP work?

I use a Yubikey to log in to a VPN. When logging in, I supply a username, and then type a password, and without hitting return, touch the Yubikey. As far as I understand, and from experimenting, the ...
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1answer
1k views

What are the privacy implications of using Yubico OTP with YubiCloud?

I am considering purchasing Yubikey devices (made by Yubico) to add two-factor authentication when my users ssh to our various servers. I figured I would configure the device to use Yubico OTP with ...
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2answers
878 views

Are Yubi Keys secure “out of the box” when purchased for use with Yubi Cloud?

The YubiKey personalization tool allows someone to configure a YubiKey for HOTP, challenge response, and a variety of other authentication formats. YubiKey offers a number of personalization tools ...
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1answer
523 views

Why can GPG sign messages but not keys?

I am trying to add local signatures to a few of the public keys I have in my keyring, but using gpg --lsign-key fails with the message "no secret key" despite the fact that gpg --sign works. I am ...
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1answer
2k views

Yubikey with S/MIME certificate

I would like to do the following. Can anyone tell me if this is possible? Store the private key for an S/MIME certificate from Digicert on a Yubikey. Backup the private key to another location. Use ...
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1answer
860 views

FIDO U2F use over multiple devices for the same service

I've been looking at the FIDO alliance's U2F specification and there's something which I can't seem to find documented. If I was to use a Yubikey or something similar as part of the authentication ...
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526 views

Can an Android Phone be used as a Windows Hello Security Key?

Microsoft Windows 10 does support physical security keys since some time. Google recently announced that Android phones can be used as security keys as well (primarily for their own services). Is ...
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55 views

2FA options for single yubikey and many hosts

I'm considering using yubikey (5 NFC model) as second factor for couple of Linux hosts. I'm interested in sticking it somewhere in PAM stack, so things like sudo are protected. Most of those hosts are ...
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2answers
228 views

GPG: Change expected card number

I have switched from a YubiKey 4 to a YubiKey 5. Both have the same GPG keys stored. After storing the key on the first YubiKey, I fetched my public key so GPG knows where to look for the private key. ...
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1answer
3k views

GPG with Yubikey smart card - smart card doesn't need to be plugged in! [duplicate]

I have created an offline MASTER key along with sub keys. The sub keys were sent to the Yubikey smartcard via the gpg 'keytocard'. The gpg --card-status command correctly identifies the information ...
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0answers
302 views

Setting up Yubikey for GnuPG on Linux Mint: Unsupported certificate

I am trying to set up my Yubikey 4 for GnuPGP following the Yubico documentation. I plugged in my Yubikey and it is recognized: $ lsusb ... Bus 001 Device 005: ID 1050:0407 Yubico.com ... However, ...
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4answers
1k views

Can you set up 2FA with a USB drive?

I want to set up two factor authentication for some of my online accounts. I don't want to install an app, and I don't like using my phone as the physical medium anyway, because it's more likely to ...
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1answer
182 views

Can 2FA keys be duplicated?

I want to order a 2FA key (like yubikey) online and I want to know if someone could make a duplicate of whatever key I order during shipping. I don't want to discuss if someone could access my package....
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1answer
869 views

Is YubiKey vulnerable to BadUSB exploits?

I know that BadUSB (revealed by srlabs.de a number of years ago) works by altering the actually firmware of a particular make of USB device, and as such my trusted systems have their own designated ...
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1answer
67 views

Conceptual question regarding signing with Yubikey/Solokey/Nitrokey using GnuPG

The named hardware dongles (or at least several models of them) allow me to store PGP secret keys key. Suppose I am using such a secret key to sign data (doesn't matter what). As I understand the ...
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1answer
77 views

2fa attestation object for non-repudiation

I am reading on digital signatures: A valid digital signature gives a recipient reason to believe that the message was created by a known sender (authentication), that the sender cannot deny ...
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1answer
276 views

Is a yubikey with OpenPGP applet more secure then saving the private key in a encrypted USB stick?

If I understand correct, Yubikey with OpenPGP applet just holds your private keys, protects them with a password and make them available through pkcs11. But what is the point of using a Yubikey with ...
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2answers
124 views

Is there a way to “lock” a YubiKey after a period of inactivity?

I have a YubiKey 5c nano attached to my laptop used for 2FA, etc. It works great and is unobtrusive, but I feel like the small form factor encourages leaving it plugged into the laptop all the time, ...
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2answers
346 views

Do PKCS #11 keyfiles on a yubikey actually improve security for Veracrypt?

I am trying to understand the benefits of a PKCS #11 keyfile stored on a smartcard such as a YubiKey with regards to Veracrypt volumes. Am I correct that the file will be taken off of the hardware ...
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0answers
59 views

Security risks of selling a used YubiKey / Factory resetting a YubiKey

I am a proud owner of a YubiKey 5 NFC and have been using it for quite some time now. I want to replace it with another YubiKey 5 NFC running a slightly newer firmware. I have utilized almost all ...
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OpenPGP and 3 Yubikeys, Best Practice for Encryption Subkey

New to OpenPGP. I have 3 Yubikeys, one for my laptop, one for my desktop, and one which I plan to keep in cold storage as a backup. My plan was to create a S/E/A subkey for each Yubikey, attached to ...
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2answers
160 views

Hardware security key with locked down usb slots

I would like to use hardware security keys in an environment where it is additionally needed to lock down any ways in which a user could download data to a device like a usb key. Is it possible to ...
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1answer
155 views

Creating pointers to keys on SmartCard

I am new to OpenPGP and SmartCards but I cannot find how to do a fairly straight-forward task. I am trying to sign a file with a private key stored on a YubiKey device. Here is my session: $ ...
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1answer
701 views

Why should I leave a U2F device always plugged in to a computer?

Over at the Yubikey website they mention that the Nano or 5C Nano series is meant to be always inserted into a computer. I've seen some other sites mention the Nano is good for servers. But why would ...
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0answers
80 views

PGP With 2 x Yuibikey 4 + 1 USB (Backup)

I have 2 Yubikey 4. I'd like to use them for PGP and overall for securing my online identity. I'm following this guide but I'm stuck at backup step. The guide itself does not explain how to have keys ...
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0answers
903 views

GnuPG “public key decryption failed: Invalid ID” using Yubikey Smartcard

I'm trying to decrypt a file that was signed with my ssb key stored on my Yubikey, but I get the following errors: x>gpg -vv --decrypt encrypted.gpg gpg: armor: BEGIN PGP MESSAGE # off=0 ctb=XX ...
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1answer
474 views

KeePassXC & Yubikey HMAC-SHA-1 vs 40+ Character Password

Looking at the implementation of the Yubikey 4 HMAC-SHA1 mode for KeePassXC, I want to know: Isn't the HMAC-SHA1 challenge response less secure than a 40+ character password? From what I know, the ...
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330 views

Weighing options for personal HSM?

I'm trying to weigh my options for a personal HSM. I wish to store both passwords and private PGP keys. I've been doing my research but I'm not a security expert and am feeling slightly overwhelmed; ...