a multi factor authentication requires at least two sets of credentials. This is typically something you know (e. g. a password) and something you own (e. g. a token generator or mobile phone), but could also be something you are (a biometric).

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81
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6answers
23k views

How secure are the FIDO U2F tokens

Google and Yubico just announced the availability of cryptographic security tokens following the FIDO U2F specification. Is this just another 2FA option, or is this significantly better than solutions ...
75
votes
2answers
12k views

How did someone log-in to my Gmail account from Kenya?

While on holiday in France in May I received an email from Google "New sign-in". Your Google Account was just used to sign in: Nairobi, Kenya. Tuesday, 26 May 2015 22:10 (East Africa Time). ...
62
votes
5answers
5k views

Do 2FA sites leak info by confirming a correct password guess?

Here's my relatively layman's view of the issue. Many websites tout multifactor authentication (MFA) as an enormous boost to the security of users' accounts, and it can be if implemented properly. ...
58
votes
6answers
8k views

Four-factor authentication

I'm sure you've all heard of two-factor/multi-factor authentication. Basically it comes down to these factors: Knowledge - something you know (e.g. password, PIN, pattern) Possession - something you ...
33
votes
6answers
2k views

Why don't PGP and SSH keys see more widespread use as a second factor when authenticating?

One of the major up-and-coming MFA methods is U2F, which relies on an initial key exchange and challenge-response mechanism. It's a relatively new protocol, and is only starting to see more ...
33
votes
2answers
4k views

Why does Google cripple the 2FA Google Authenticator PAM module?

If you enable 2FA for Google Apps the shared secret is 160 bits. The google_authenticator PAM module on the other hand seems to use 80 bits for the shared secret. According to RFC 4226: R6 - The ...
32
votes
3answers
31k views

How does HSBC's “Secure Key” actually work?

My bank has recently sent me a Digipass/Secure Key, which looks like a tiny calculator. You press the green button to turn it on, type a PIN to unlock it, then press the green button again to generate ...
32
votes
11answers
4k views

Is it safe to use a weak password as long as I have two-factor authentication?

I'm careful to use strong passwords (according to How Big is Your Haystack, my passwords would take a massive cracking array 1.5 million centuries to crack), I don't reuse passwords across sites, and ...
27
votes
4answers
7k views

What is a YubiKey and how does it work?

How do YubiKeys work? Are there any alternatives?
26
votes
4answers
3k views

How is “something you have” typically defined for “two-factor” authentication?

A wide range of products claim to offer "two-factor authentication" (c.v. Two-factor authentication - Wikipedia). Most are deployed as "something you have" to be used in addition to a normal password ...
23
votes
14answers
4k views

Why do we even use passwords / passphrases next to biometrics?

In the last couple of days there were a lot of talking about passwords and passphrases, not only here, but on several blogs and forums I follow (especially after XKCD #936 saw the light of this world)....
21
votes
2answers
3k views

Which SSH security is stronger? 2 Factor or Public key

For SSH authentication, which is more secure? 2 Factor Authentication using a USB token/Google Authenticator(time based) OR Public/private key with password Or could they be both used at the same ...
20
votes
4answers
3k views

Why use a Smartcard for (Two Factor) Auth instead of another medium?

I recently installed Bitlocker on my Windows 8.1 machine, using only a password. I was thinking of getting something other than just a password for my storage drive, something physical, like a USB, SD ...
19
votes
11answers
4k views

2 factor authentication - cost effective solution for a web startup [closed]

My local bank uses a 2 factor authentication where customers key in password AND a One Time PIN delivered via SMS to mobile phone OR from a security token device. I am doing a web startup in the ...
19
votes
4answers
2k views

Biometric versus other Two Factor Authentication Mechanisms

Over the years biometrics is the go-to movie authentication mechanism, but in the real world I'm getting conflicting opinions about it. Everything I've learned shows that biometrics are flawed ...
17
votes
6answers
3k views

What extra security does a 2-step website login process with a PIN provide?

I am currently working on a web application with a significant security risk attached to its function. We're using Microsoft Identity Framework to handle user logins, with the system forcing strong ...
17
votes
3answers
1k views

Multi factor authentication on Ubuntu workstations, where to start?

Is it possible to have Ubuntu users log in with multi-factor authentication? I was thinking of a combination of pass(word|code) and smartcard (with screen locks when for example smart-card is removed) ...
16
votes
2answers
605 views

Mitigating the loss of a mobile phone used for second-factor login

Take the following scenario: John is using GMail for his primary email account and LastPass as his password management system. Both of these accounts are using the Google Authenticator mobile ...
16
votes
1answer
1k views

Do any DNS registrars support multi factor authentication?

I am looking for a DNS registrar that supports strong multi-factor authentication. Does any DNS registrar support multi-factor? Is this a legitimate need?
15
votes
5answers
1k views

Does two factor authentication prevent social engineering attacks

After reading this article from symantec I got to think how much all these social engineering techniques rely on the authentication system of users, a password. Considering three different additional ...
15
votes
6answers
10k views

How to implement multi factor authentication using a token generator?

I'd like to implement multi factor authentication on a few projects. Now the first factor would be username and password, for the second factor I would like to use a token generator. These tokens ...
15
votes
4answers
5k views

Three-Factor Authentication for Windows

This HowToGeek article... http://www.howtogeek.com/67556/how-to-unlock-your-pc-by-being-nearby-with-a-bluetooth-phone/ ...got me thinking. Is there any software (or combination of software) that ...
14
votes
6answers
2k views

Additional security benefits from Multi-Factor Authentication?

Does multi-factor authentication provide any additional security benefits on top of doing a better job at correctly identifying and authenticating users compared to single factor authentication? In ...
14
votes
5answers
1k views

Safe way to authenticate (multi-factor authentication?) while being monitored?

(I'm trying for a bit more precise answer, particularly with regard to multi-factor authentication, than I received for "Safe way to use a computer that has spyware/keylogger installed?" on SU.) Let'...
13
votes
9answers
862 views

Anybody have additional information on the EMC RSA SecurID compromise?

The Security Advisory Press Release here doesn't have much information, the email that alerted me to this didn't help much more, and unfortunately I heard about the two Thursday evening conference ...
13
votes
4answers
2k views

Which verification method should I choose: SMS or call?

I want to enable Two-Factor Authentication for my outlook account, but I'm not sure which method should I choose or in other words which method is more secure? Like I said there are two options: text ...
13
votes
2answers
1k views

Does having 2-factor authentication help with HeartBleed?

I was talking with a friend about HeartBleed, and he mentioned that he had 2-factor authentication enabled on all the sites that supported it, so even with his username and passwords, nobody would be ...
12
votes
4answers
1k views

What is the use of the “secret” displayed when setting up 2 Factor Authentication?

What is the purpose of the "secret" that is displayed when you take the picture of the QR code to set up 2 Factor Authentication on a non-Google site? Why would you need it? If you save it, doesn't ...
12
votes
3answers
2k views

What is the risk and mitigation of accidentally typing a YubiKey password in an open forum?

I have a YubiKey in my laptop (for testing) and accidentally broadcast my YubiKey password out to the Internet. Since this is only a test key, and has no access to anything of value, here are some ...
11
votes
3answers
859 views

Steam and two-factor authentication

The Steam platform is designed to encourage users to use two-factor authentication. One of the community tasks (achievement-like objectives) on Steam is "Use the Steam Mobile App for two-factor ...
11
votes
6answers
6k views

Is tokenless (specifically SMS) 2FA a security compromise over OTP tokens?

I've been looking into the various pros/cons of tokenless (particularly SMS based) and traditional token based two-factor authentication (think RSA SecurID). After doing some research, I think I have ...
11
votes
4answers
8k views

Does adding two-factor authentication by OTP really make KeePass more secure

KeePass is an application that keeps all your passwords for you in a database. It is primarily protected by a master password and/or keyfile. If the database is properly encrypted with that password ...
11
votes
5answers
1k views

Non-OEM Biometric Software?

Most of us with fingerprint readers and such devices probably use the software provided by the vendor, to enable biometric OS login or single sign-on functionality. However, I've recently wondered if ...
11
votes
1answer
710 views

Yubikeys & SSH - which option is best for lockdown?

My company has a few dozen servers hosted on a cloud provider. All but one (OpenVPN host) is closed to the internet. We're using OpenVPN AS which uses certs + Google Authenticator for login. We are ...
10
votes
5answers
1k views

Is a biometric eye scan more secure than a multi-factor authentication

I have come across the following question in a Security+ exam guide You are tasked with creating a high-security authentication system for physical access control to a military installation. Which ...
10
votes
5answers
566 views

Two passwords provide better security than two-factor authentication?

While evaluating 1Password's new Teams service, I noticed rather curious absence of support for multifactor authentication. When asked about the lack of MFA, they replied: We use an Account Key ...
10
votes
2answers
3k views

LastPass Grid Authentication vs Google Authenticator which one is more secure?

[Being a LastPass user] recently I moved to Google Authenticator instead of using Grid Authentication as a 2-factor security. For me, finding and filling letters from such a dense matrix is a rather ...
10
votes
3answers
961 views

If multi factor authentication is enabled, how should that affect self-service password reset?

Given that security is only as secure as its weakest link, suppose I have website with additional authentication enabled in any of these ways: (example, multiple conditions may be required) SMS/...
10
votes
2answers
2k views

How does Google detect new devices for two factor authentication

When you enable two step verification for google accounts, you get sent a code by SMS to enter in addition to your username and password the first time you log in with a new device. How do they ...
10
votes
1answer
3k views

What are the differences between the U2F and UAF FIDO authentication standards?

Google recently announced support for Universal 2nd Factor (U2F) authentication in Chrome and started allowing that authentication mechanism to be used for 2-factor authentication across their various ...
10
votes
2answers
2k views

How do I protect my Gmail account when accessing it via an Android smartphone?

I have a Gmail account that I also access via an Android smartphone. The mail account could be used to reset passwords for other online accounts, so I want to tighten up the security around this ...
9
votes
6answers
1k views

Is there multi-factor authentication for machines?

Most of what I have seen on mutiifactor authentication (eg wikipedia or here on se) seems human centric. Ie it is a human interacting with a machine and the factors are associated with authenticating ...
9
votes
4answers
382 views

What kind of factor is a physical signature?

I'm familiar with the basics of multi-factor authentication. Now I'm trying to understand how a physical signature, as written on, say, a check or a credit card receipt, would be classified: Is it ...
9
votes
3answers
328 views

What advantage does the Bloomberg authentication system have over traditional 2 factor?

Bloomberg clients have an interesting way to authenticate to the server. This seems involve some of the following: Logging into a secure website, that displays a flashing square Swiping your finger ...
9
votes
2answers
8k views

How does Authy's 2FA work, if it doesn't connect to the server?

I thought I knew how two-factor authentication works: I enter the password. Server generates a random number (token) and sends it to me via SMS. I enter this token. Server checks that the token I ...
9
votes
6answers
2k views

POP3/IMAP Stronger Authentication

We recently deployed a two-factor-authentication solution in order to strength logon to our web applications (one of them is web based mail, Microsoft outlook web access) Most of the users who have ...
9
votes
2answers
3k views

How to fix a repeatedly hacked gmail account (where 2FA is enabled and passwords are changed)?

A friend of mine came to me for help with this issues. Her Gmail account has been hacked and keeps sending out spam emails to her contacts. This is happening to her on a monthly basis. Each time it ...
9
votes
2answers
2k views

Do keyfiles actually add any meaningful security in the presence of strong passwords?

In the context of protecting access to local encrypted files or devices against a determined (and competent) adversary, is there any reason to believe that the use of a key file actually presents a ...
8
votes
1answer
772 views

How safe is “trust this computer” option for websites?

Many sites have a "trust this computer" option that allows one to bypass some security measures (ex.: with Google's 2-step authentication enabled, one does not need to enter the phone's code if the ...