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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2
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5answers
124 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 ...
10
votes
2answers
971 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
vote
0answers
21 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 ...
-1
votes
1answer
39 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
votes
1answer
93 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 ...
0
votes
2answers
503 views

How does Authy works?

I think I knew how does two-factor authentication works. I enter the password. Server generate random number and send me it me by sms. I enter this number. Server check number I entered with ...
1
vote
2answers
51 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 ...
-6
votes
1answer
106 views

How can I succesfully pentest site with two factor authentication? [closed]

I want to use a commercial, automated tool but it cannot login successfully because the website requires a two factor authentication process using SMS. For testing, the SMS message is sent to another ...
3
votes
3answers
256 views

Does Google/Dropbox/Github Two-Step Verification count as Two-Factor?

This considers the route where somebody does not use the SMS option, but rather using TOTP, and the site offers a generated seed to input. Two factors questionably at use: password: something KNOWN ...
0
votes
3answers
113 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 get ...
0
votes
1answer
100 views

Two-factor port-knocking via SMS (TXT)

It seems to me that a useful alternative or supplement to traditional port-knocking, fwknop, etc, for a system requiring only occasional access, would be to: Set up a one-time pad of keys, and a ...
32
votes
2answers
1k 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 ...
0
votes
1answer
41 views

Securing data on a mobile device (even from the user/owner)?

I am writing an application to generate OTP codes for two factor authentication where I need to securely store data locally. This data must be secure from both the owner/user as well as intruders. I ...
1
vote
2answers
136 views

Does this show the need for a two-factor authentication?

I need some help for my understanding while reading through this authentication scheme in WEP. In a WEP authentication scheme, the station first sends a request for authentication. However, this ...
3
votes
2answers
346 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 ...
4
votes
2answers
2k 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 ...
0
votes
1answer
118 views

What are techniques for end users to select keys on a smartcard?

When multiple keys exist on a given smartcard, how can a user choose between them for a given identifier ... ideally without a loss of privacy? For example suppose I have a government issued ID that ...
9
votes
4answers
576 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 ...
0
votes
2answers
291 views

Do Google 2 Factor Auth backup codes work for logging into Google or other sites?

I set up Google 2 Factor Auth to log into other sites. I see there are backup codes if you lose your device. Are these used only to log into Google, or can they be used to log into other sites?
-2
votes
2answers
246 views

Why doesn't Google 2 Factor Auth ask for a code? [closed]

I set up Google 2 Factor auth to use 2 Factor Auth with certain sites. But reading over the help suggests that Google 2 Factor Auth is only used to log into Google services like Gmail. But when I log ...
5
votes
4answers
478 views

One time password over SMS - exposing the Authentication Server to the internet

Consider a Internet Based Website which does authentication. The Web Application can do the authentication by calling an Authentication Server which is not connected to the internet. The ...
9
votes
2answers
328 views

NFC used in place of contact based smart card two-factor authentication

My organization is trying to move away from contact based smartcards (because our hardware vendor is no longer integrating them into their current systems) to some other form of two-factor ...
2
votes
2answers
427 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 ...
5
votes
2answers
229 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 ...
6
votes
2answers
1k views

How do I block LinkedIn from extracting data from Microsoft Exchange Server?

LinkedIn now offers the ability to take a real user and password from the end user and connect to Exchange Server for the purpose of importing contacts into their system. (To do this yourself, click ...
2
votes
1answer
313 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 ...
15
votes
2answers
381 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 ...
5
votes
5answers
3k views

What are the ways to implement two factor authentication?

We have devices that can generate tokens. So we can use tokens with passwords to perform two factor authentication. There are many ways to implement such systems to enhance security. One of two I ...
8
votes
6answers
516 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 ...
1
vote
1answer
251 views

What is more secure for voice and SMS OTP: A random number or generated similar to HOTP?

Many providers are creating OTP authentication for their sign in. However I noticed that all the voice and SMS OTPs I've come across are a series of 6 digits... similar to the HOTP RFC Standard ...
9
votes
2answers
776 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 ...
4
votes
2answers
118 views

Options for simple phone verification with pin delivery

My website needs to verify phone numbers in order to ensure that customers claiming a business actually work there. The service calls and gives the customer a pin which they put into the site. Many ...
8
votes
3answers
273 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) ...
-1
votes
1answer
148 views

Does PayPal support a backup code for two-factor auth? [closed]

Google and DropBox have backup codes in case you can't get access to one of the devices you have registered. Does PayPal have a backup code?
3
votes
1answer
195 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 ...
4
votes
5answers
250 views

When should I issue more than one multi-factor device to a user? Is it OK to give several active tokens vs none at all?

Most of the conventional IT.Sec thinking I've seen says that a user can only have one multi factor authentication device. I'd like to challenge that defacto-thinking and ask if there is ever an ...
5
votes
1answer
186 views

How to solve race condition in 2-factor authentication solutions like RSA Security tokens or Google Authenticator?

One of the reasons we opt to use 2-factor authentication is to minimize the impact of keyloggers. The theory is that even if an attacker is able to observe the user type in the token numbers, they ...
4
votes
1answer
323 views

Can I re-use another vendor's dual factor token in my own system? (Avoid physical token bloat)

I read the open source multifactor authentication techniques called HOTP RFC 4226 and TOTP RFC 6238 and realized that a single random number is the basis for the token's cryptography... and that this ...
3
votes
2answers
117 views

Should the serial number of multi factor devices be removed?

I'm trying to understand the relationship between the serial number of a multi factor device and the cryptographic material behind it. I don't want to blindly assume that the serial number is just ...
2
votes
1answer
2k views

Is it secure to install RSA SecurID Software Tokens on the same computer that will be used to access the VPN?

My office switched from using the old hardware RSA SecurID key tokens to the RSA SecurID Software Tokens and most users have them installed on the same machines they use to access the VPN. I asked ...
1
vote
1answer
405 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 ...
15
votes
2answers
1k 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 ...
4
votes
1answer
113 views

What physical, electronic, and software characteristics are important in a smart card?

I'm evaluating smart card readers to store a number of private keys, but don't know where to start. What criteria is important regarding smart cards and preventing the extraction or unauthorized used ...
13
votes
3answers
685 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?
6
votes
5answers
504 views

Is behavioural analysis (e.g. keystroke dynamics) a reliable security mechanism for MFA?

The typical set of multi-factor categories is as follows: Something you know (e.g. a password) Something you have (e.g. a hardware token, or key file) Something you are (e.g. a fingerprint or retina ...
5
votes
2answers
630 views

Does having a passphrase and SSH key qualify as two factor authentication for PCI?

I am working on getting our company's servers PCI SAQ-C compliant (credit card data passes through our system but is not stored by our system). We have SSH access to administer the servers and all ...
2
votes
1answer
403 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 ...
3
votes
2answers
525 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 ...
12
votes
3answers
7k 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 ...
22
votes
11answers
2k 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 ...