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)

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Should a 2FA recovery key be stored along with a password?

Many websites give you a recovery key or a list of recovery codes that can be used in place of 2FA tokens if you lose your phone or can't access your token generator. What are the recommended ...
0
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1answer
39 views

Are 2FA soft-tokens flawed if the user can log into the website from the same mobile device?

If I'm using something like Authy for soft tokens for my users, and they log into the web application on the mobile device itself, haven't they just lost the benefit of 2FA (ie loss of the mobile ...
1
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1answer
192 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 ...
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4answers
3k 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 ...
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6answers
6k 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 ...
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4answers
1k 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 ...
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1answer
53 views

Is selecting trusted computer in 2-step verification less secure?

In using 2-step verification, does selecting 'Trusted Computer' a less secure options? https://support.google.com/accounts/answer/2544838?hl=en If so, is it still a reasonably secure option?
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1answer
159 views

How can LastPass enforce 2-factor authentication

I've recently started using LastPass and one of the things you can set as a policy for you password vault is Prevent offline access when using Google Authenticator. The local cache can be ...
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5answers
102 views

SSH server: What's more secure, pub key auth or Google Authenticator time-based auth?

I'm curious which would be more secure, pub key authentication or 2-factor auth via Google Authenticator. Apparently I can't use both. If I have pub key authentication, the Google Auth PAM module ...
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3answers
238 views

How to evaluate different solutions for security tokens?

According to my own experience, most companies selling security tokens for authentication like RSA, Verisign or Aladdin share little information about the internals of their products like algorithms ...
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1answer
32 views

Can OTP 2FA be reversibly determined?

Please note: I'm not necessarily talking about what happens when one shoulder surfs someone inputting a OTP. I'm fairly confident that it's nearly impossible (or extremely impractical) to guess the ...
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2answers
2k 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 ...
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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 ...
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1answer
520 views

Is TextKey SMS 2 factor authentication secure against cell phone cloning?

I came across this website today that implements SMS based authentication that works "opposite" most SMS authentication methods. In typical SMS authentication, the provider sends you an access code ...
7
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0answers
172 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 ...
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4answers
200 views

Isn't it less secure to use something you are for authentication?

I have to think of this everyday when I close the doors of the shop I work in: A year ago we used to close the shop and arm the alarm using a key fob. This means the worst case scenario was that I ...
9
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4answers
241 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 ...
2
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2answers
100 views

Where can 2-factor fail in Google?

I was one of the people who thought that enabling 2-factor in Apple would have prevented the download of images from iCloud; it was recently pointed out to me that, in fact, I was gravely mistaken. ...
14
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6answers
1k 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 ...
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2answers
595 views

Could “receive SMS online” site be a scam?

There is a site that allows you to see all SMS received by a certain set of phone numbers (owned by the site). This seems to be meant for services that require two-factor authentication using SMS, ...
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5answers
419 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 ...
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11answers
3k views

2 factor authentication - cost effective solution for a web startup

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 ...
0
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2answers
75 views

Are there any flaws in my design for a paper-based OTP grid?

I'm trying to implement two-factor authentication on the cheap for a website of mine. My bank uses this sort of grid-based OTP system, so I wanted to emulate it in my application: Cards are ...
10
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2answers
886 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 ...
3
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1answer
190 views

Do non-browser clients work around Gmail's 2-factor authentication?

If you use a client like mutt to access your mail, you probably know that it doesn't support 2-factor authentication. It still prompts only for a password - either your account password or, in the ...
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0answers
52 views

Generating backup codes for a 2FA implementation

I have implemented the login/verification aspect of a two factor auth system as per RFC 6238. It works fine with Google Authenticator, which is great. Now I am turning my attention to the backup ...
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1answer
28 views

How VIP card helps in verification? [duplicate]

How does the 6 digit randomly generated security code from (disconnected) Verisign Identity Protection card help in verification/validation of any user? Why one cannot enter any random 6 digit ...
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3answers
1k 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 ...
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3answers
129 views

Is login limiting still needed if we employ multi-factor authentication?

The status quo is that most online websites limit login attempts per IP address, or even per account since some attackers possess huge amounts of IP addresses. OWASP declares: When multi-factor ...
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1answer
40 views

Does RADIUS allow for eventual, gradual adoption of 2 Factor auth in an AD Environment?

We have several applications that leverage AD SAML (via Ping Federate) LDAP authentication from 3rd party applications Windows workstation / Exchange auth (Kerberos) IIS and web components ...
2
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3answers
118 views

Multi-factor auth: implementing a “don't ask again for this computer” function

Many sites that support multi-factor authentication provide a "do not ask me again for this computer" option. I'm hoping to gain some insight into how this feature could best be implemented. My ...
3
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6answers
264 views

Why not ask for a password and 2-factor token at the same time?

I have observed a number of web-based login forms that offer 2-factor authentication do token entry on a second form after validating your username and password. Is there a reason not to ask people ...
7
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6answers
908 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 ...
0
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2answers
134 views

Creating port-specific SSH authentication for the same user

I have a Linux server running SSHD and would like to know if its possible to configure it, such that from within the LAN you only need a RSA key to authenticate (on port X), but from outside the LAN ...
4
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3answers
700 views

Two-Factor Authentication: When is it worth it?

I was reading this article, and it triggered the question: Why not use two factor authentication? In his case, it both possibilities were enabled anyway, so this looks to me like it's two attack ...
2
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1answer
529 views

Is Dual Factor possible during boot with whole disk encryption on Mac FileVault 2

Mac FileVault 2 is the default disk encryption for newer Macs that occurs in the EFI pre-boot phase. The challenge here is that most smartcard drivers are loaded after the OS loads. Is anyone aware ...
14
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4answers
3k 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 ...
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3answers
70 views

Is it ok to use the same password for many services with two-factor authentication?

Let's say that I've a relatively strong password, but I don't want to use many different passwords for each different service, and let's say that those services provide two-factor authentication using ...
2
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2answers
131 views

Does Google 2-step verification protect user from session hijacking?

After signing in Google 2-Step verification scenario, user should enter verification code which sends to his mobile. Without it, he couldn't access to Gmail account. Consider an attacker does session ...
18
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3answers
13k 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 ...
4
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2answers
565 views

Is OATH TOTP and / or Google Authenticator vulnerable if an attacker has (N) previous codes?

I'm not much of a ipsec initiate, so this is a bit over my head ... but I'm always willing to learn more. Are there any known attacks against OATH TOTP (Google Authenticator's / Authy's algorithm) if ...
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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 ...
1
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0answers
40 views

Is there a TOTP variant that does not require the user to type in a code? [closed]

We're considering a 2 factor TOTP solution on a mobile phone. However, it would be much easier for the user to somehow send the OTP to the server by pushing a button, rather than manually typing in a ...
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1answer
56 views

Is it applicable to use Google Authenticator against TEMPEST?

I would like to know about Multi-Factor Authentication is applicable for TEMPEST or not. Why I'm asking is I have suspicious matter every day also captured as log. My concern: It's possible to ...
0
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1answer
122 views

Using Gmail in China triggered lots of Two Factor SMS

A friend of mine lives in Hong Kong and she travelled to China over the weekend. Whilst there, she was able to use Gmail on her Android phone without logging in again, but she had to re-login on her ...
15
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5answers
820 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.) ...
9
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6answers
719 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 ...
14
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6answers
7k 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 ...
32
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2answers
2k 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 ...
2
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2answers
67 views

HOTP/similar - how about standard backups of mobile devices?

I was considering adding HOTP as an option to my website (alongside things such as SMSed one time tokens which I already have). But I was considering one issue that HOTP inherently has: Things such ...