Authentication - establishing the authenticity of a person or other entity. Not to be confused with authorization - defining access rights to resources.

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2answers
879 views

BCrypt's 72-character limit and using it as a general digest algorithm

Goal: have token/cookie-based authentication that doesn't require keeping sessions on the server TL;DR: What, if any, is the accepted mechanism to work around the 72-character limitation of BCrypt? ...
11
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3answers
797 views

How much information about the reason for an unsuccessful login should a web application give?

After an unsuccessful login attempt, should I inform the user about its reason? Or more generally, how much information about the reason for an unsuccessful login attempt should a web application ...
11
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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 ...
11
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4answers
1k views

Multiple CAs signing a single Cert/CSR?

Just saw this suggested on Slashdot So I've seen quite a few people wanting a switch to self-signed certs (who IMO mostly don't understand what making that secure actually involves), and an idea ...
11
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3answers
5k views

How does deauthing work in aireplay-ng?

I have a question of how aireplay-ng works when it deauths. I mean, it is really easy to disconnect another client from an AP: you just need to run the deauth command (in aireplay-ng) once, specifying ...
11
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1answer
1k views

When authenticating ciphertexts, what should be HMACed?

Some have argued for using AES-256-CTR with HMAC-SHA-256 for authenticated encryption over AEAD-specific modes like EAX and GCM. However, when doing, this, what should be HMAC'd? And how? ...
11
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5answers
714 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
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2answers
2k views

What are the dangers of allowing “less secure apps” to access my Google account?

According to https://support.google.com/accounts/answer/6010255: Google may block sign in attempts from some apps or devices that do not use modern security standards. Since these apps and devices ...
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4answers
3k views

Authenticating without a database

I've been inspired by a question over on Code Review, which boils down to: What is the proper way to authenticate a user without a database? Would it be the exact same process if you stored ...
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9answers
1k views

Why do we authenticate by prompting a user to enter both username and password? Does prompting the password only suffice?

I don't know why do we authenticate by prompting the user to enter both username and password. In my mental model, prompting password only suffices. The reason is as follows: Assume there are x ...
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7answers
5k views

Forgotten password or reset link, which is more secure to email?

I originally posted this as a reply here in this thread but didn't get much feedback on it, and now I'm curious as to what others think is the best approach, or if there is any difference between the ...
10
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6answers
2k views

Prevent denial of service attacks against slow hashing functions?

I've been thinking about bcrypt recently, and what I wonder is if there's a way to deal with the inherent (D)DoS problems with slow hashing functions. Namely, if I set up bcrypt so my machine takes ...
10
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5answers
2k views

CSRF protection with Session Id

To protect against CSRF, couldn't my page javascript just dynamically insert the session id from the cookie into the body of each HTTP request right before it's sent? The server would then just ...
10
votes
4answers
6k views

Security measures against packet sniffing

I work in a environment where packet sniffing can be easily done . I was worried about my confidential data . Please suggest how is it done and precaution which i can take at client level.
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votes
3answers
3k views

How does an SSL server prove its identity?

This document says that a challenge response authentication proves the servers identity. But is a man in the middle attack still possible if the client does not verify domain name ? Please help me ...
10
votes
4answers
2k views

How can an access point spoof me into connecting?

I was reading through the answers of the question "How can I ensure that I connect to the right wireless Access Point?" and was wondering how it is possible for an access point to imitate another wifi ...
10
votes
4answers
693 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 ...
10
votes
5answers
2k views

How can I securely authenticate the client application sending me data?

We have a web service logging/recording user data sent over https by our client application. Is there a way to securely ensure that the data is getting sent by the client application and not by a fake ...
10
votes
4answers
12k views

What is the difference between authenticity and non-repudiation

I'm new to infosec and doing some reading. Not surprisingly one starting point was wikipedia. In this article, authenticity and non-repudiation are listed as 2 separate 'Basic concepts'. My ...
10
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4answers
782 views

What is the key when facial recognition is used as a password?

I get the basics of what face recognition is and the fact that it is used to protect PC's and as a login replacement. However, if it was to be used for encryption, where the role of the key is played ...
10
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4answers
1k views

Can .htaccess and .htpasswd really protect me?

I want to set up a kind of personal wiki where I can store various sensitive information. However to make it 100% portable and and just plain convineant, I want to put it on the Internet. I'm sure at ...
10
votes
2answers
901 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
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2answers
3k views

Role Based Authorization vs. Claim Based Authorization

What is the difference between "role based authorization" and "claim based authorization"? Under which circumstances would it be appropriate to implement each of these authorization models?
10
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3answers
371 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) ...
10
votes
6answers
11k views

Securing an API for mobile access

I've built a nice REST/JSON API that is used by other companies (our clients) as a B2B service. Each of our clients has a username/password pair, and we also do HTTPS and validate the source IP of ...
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3answers
300 views

Is there any conceivable reason to prevent a password change in an authentication system?

I connect to the VPN of another company with a company-specific username and password (they aren't giving everyone the same password to every company to access it or anything ridiculous like that.) ...
10
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2answers
256 views

Preventing Voter Fraud on a Social Media Contest

I'm creating a contest that will allow users to login using their Facebook & Twitter accounts and submit votes on videos. My clients concern is that users will game the system by logging into ...
10
votes
1answer
265 views

Is this cross-site password model secure?

I'm looking for a way of securely having passwords for different pages. Say I generate this password: ild23rfsfdfg%*#fArg34t34657%537@asd7oak2094^*q2k2k@Kk3j4tn453Q5# Then, for each site, I change ...
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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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4answers
1k views

Location to store an encryption key

I'm building a secure system which stores messages on a server in a Postgresql database. The messages are stored encrypted with PHP's openssl_encrypt() function with the AES-256-CBC method. At the ...
10
votes
4answers
5k views

What are the disadvantages of single sign-on authentication?

We were discussing to implement single on in our web application,right now after analyzing we came to know that the following were the advantages of single sign on authentication. Advantages Users ...
10
votes
2answers
620 views

Security of unencrypted wireless networks with authentication page

Some wireless networks, such as those offered by hotels and hotspots, are not encrypted (they don't require a pass phrase to connect) but have an authentication web page. For example, you connect to ...
10
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2answers
414 views

“Pulled from public record” security questions

Several times in the past months, I have been asked security questions that are "pulled from public record" to verify my identity, either over the phone or on a website (Chase Bank, Walgreens ...
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3answers
1k views

API message verification without storing private key?

I'm in the process of implementing a public API for my web service. Security is a key concern as money is involved. It seems the current common practice for "authenticating" users in API requests is ...
9
votes
3answers
5k views

How can i find what hashing algorithm was used?

One of my clients has asked me to modify the login page that their board members use to access their materials. The problem here is that the person previously responsible for this has left no ...
9
votes
4answers
2k views

Is Facebook Connect or Twitter OAuth PCI Compliant?

We have a system that stores credit cards securely on file. We'd love to allow users to sign up using Facebook Connect or Twitter. Obviously this wouldn't be secure if we were trusting just any old ...
9
votes
7answers
483 views

Authencity of information displayed on an untrusted device

Suppose I have a (bluetooth/usb) device which needs to displays information on an external pc/phone. Is there a simple and effective method to garantuee that the information displayed hasn't been ...
9
votes
6answers
1k views

What methods can be used to prevent mistyped usernames?

I wanted to log on to my account on my bank's website. The account is protected by a number of security checks. The first one is what really amounts to a username, a confidential one. It's an 8-digit ...
9
votes
2answers
803 views

My bank makes me enter my password using the mouse. What's up with that?

Internet banking login process for Westpac requires user to enter the password using the mouse. It's annoying, what's up with that? Is it just to try and stop keyloggers on public computers or is ...
9
votes
6answers
724 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
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3answers
1k views

Is SiteKey a valid defense against Phishing?

As described here, some banks use a SiteKey mechanism in an attempt to provide a defense against phishing. (This is a scheme where the user is shown a personalized image (each user has their own ...
9
votes
3answers
3k views

Is HTTPS and Basic Authentication secure enough for banking webservices (RESTful)?

I have been reading about SSL/TLS for the last few days and looks like it has never been practically cracked. Given SSL/TLS is used for all communications between client application and the server, ...
9
votes
3answers
2k views

Any flaws in this security model for a REST web service?

I have designed a REST web service which requires authentication. It handles authentication in a manner similar to Amazon Web Services, namely: the user has an ACCESS_KEY (say, 'abcd') and a ...
9
votes
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 ...
9
votes
2answers
2k views

Kerberos authentication over the public internet

What are the threats to having the KDC accessible via the internet for remote clients? It's my understanding that the authentication is a challenge/response protocol and that the password is never ...
9
votes
1answer
42k views

Can the Gmail password be recovered from the Android Gmail app?

I have an Android device with the Gmail app installed. This app can access the mailbox so there must be some kind of authentication data stored on the device (possibly an application specific ...
9
votes
2answers
5k views

How to set up OpenSSH to use x509 PKI for authentication?

I do not mean simply putting the public RSA key of a x.509 certificate into ~/.ssh/authorized_keys - I'm looking for a way to set up a ssh such that x.509 certificates signed by a pre-defined CA will ...
9
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1answer
565 views

How secure is Windows 8 email authentication?

I boot up Windows 8 and the first thing I notice is that it allows you to login with your email credentials. Let's say if my laptop is stolen then what are the advantages or disadvantages of email ...
9
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4answers
441 views

How should I tell an organisation that they are vulnerable when I wasn't given permission to check?

I was recently at a village hall (in the UK), some distance from where I live, for a party. I noticed that they had unsecured wi-fi with an SSID of NETGEAR. I assumed it was free wi-fi for users of ...
9
votes
3answers
1k views

HMAC Based Request Signing - Storing the Salt

I'm working on a (non high security) project that currently isn't live but might go live at some point. We have a REST API (implemented using Restlet and Neo4j) running on a server and an Android ...