0
votes
2answers
57 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 ...
0
votes
1answer
58 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 ...
3
votes
1answer
86 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 ...
3
votes
3answers
87 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 ...
0
votes
2answers
84 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 ...
1
vote
2answers
421 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, ...
1
vote
3answers
60 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 ...
7
votes
2answers
484 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
votes
6answers
226 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 ...
11
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 ...
3
votes
2answers
1k 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 ...
4
votes
3answers
325 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 ...
-2
votes
3answers
139 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 ...
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 ...
1
vote
2answers
158 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 ...
4
votes
2answers
482 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 ...
10
votes
4answers
649 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
337 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
329 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 ...
9
votes
2answers
403 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
522 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 ...
6
votes
2answers
302 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 ...
2
votes
1answer
408 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 ...
8
votes
5answers
4k 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
635 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
323 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 ...
10
votes
3answers
946 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 ...
10
votes
3answers
316 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
190 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?
4
votes
5answers
265 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
207 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
403 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
141 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
489 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 ...
6
votes
5answers
600 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 ...
6
votes
2answers
722 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 ...
4
votes
3answers
618 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 ...
23
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 ...
7
votes
6answers
794 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 ...
7
votes
6answers
3k 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 ...
6
votes
2answers
3k views

Full disk encryption and multi-factor authentication

All serious full disk encryption schemes I have looked into use a static password for authentication. For example, TrueCrypt supports two-factor authentication with keyfiles, but not for system ...
2
votes
5answers
720 views

Do any organizations use Smart Cards other than the military?

The military's Common Access Card (CAC) seems legit. Do other companies/organizations employ their use? If not, why? UPDATE What are the pros/cons of smart cards, compared to other methods?
5
votes
2answers
965 views

How does multi factor authentication modify the AD authentication process?

I'm trying to understand what would have to be updated to make Windows-based systems support multifactor authentication. Possible things that might have to be modified: Active Directory / Domain ...
1
vote
1answer
111 views

Should the email server/application be protected by 2 factor authentication? What applications should be protected?

When should email be protected by 2 factor authentication? Suppose a given company is in an industry where two factor authentication is offered to some or all of its clients. Does this mean that it ...
2
votes
2answers
388 views

Restrict user login to a specific machine

How do you restrict user access to a corporate web site to a particular machine ? including the following conditions : Each user is meant to use his credentials ONLY from the assigned machine. The ...
2
votes
2answers
2k views

Synchronous and Asynchronous physical security tokens: which is stronger? pros/cons?

I'm thinking about the differences between physical authentication tokens such as RSA's synchronous physical tokens or asynchronous challenge/response, like Google's gmail direct-to-phone codes. At ...
4
votes
1answer
352 views

How many authentication factors are there?

The three classes that we all know and love: Something you know. Something you have. Something you are. I've also seen references to "somewhere you are". Is this really a fourth factor? How many ...
13
votes
6answers
6k 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 ...
18
votes
12answers
2k 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 ...