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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3answers
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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? ...
13
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5answers
450 views

I need ideas for blocking a single malevolent user

Let me throw out this problem I'm having to some of my technical peeps and see if you guys have any new suggestions: We have a website that sends text messages and voice mails for our clients. ...
13
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2answers
477 views

Why should one avoid chains of SSH sessions?

In this document on Security on NSC computing resources, there are several obvious pieces of advice (use a strong password, don't repeat passwords, etc.). One piece of advice I have not seen before, ...
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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 ...
13
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3answers
14k views

How secure is Android's facial recognition?

Android supports using facial recognition for unlocking your phone. How secure is that mechanism? For instance, if someone has a good quality picture of your face, can they defeat the facial ...
13
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4answers
5k views

How do the STS token formats compare to each other SAML vs SWT vs JWT?

I'm configuring an Azure ACS STS and would like to know if there is any impact on security based on the following token formats or how they are used. The answers to this questions should apply to ...
13
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3answers
6k views

OAuth2 - Resource Owner Password Credentials grant

The OAuth2 spec describes the Resource Owner Password Credentials grant type and authorisation flow here. I understand that only 'trusted' client applications would be allowed to use this grant, for ...
12
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5answers
2k views

What is the best way to transmit password hash over unreliable TLS?

I have TLS connection between my server and client. I have no certificate, so the connection is susceptible to the Man-in-the-middle attack. I fear that attacker could intercept the password hash ...
12
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9answers
2k 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
30k views

Can my email account be accessed without the password? How secure is it?

Can my email account be accessed without the password, and how secure is email if I store my personal documents on it? And how come Yahoo Mail asks me to tell them my friends and folders names to ...
12
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7answers
3k 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 ...
12
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4answers
14k 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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1answer
2k views

Fell for phishing scam. Is my gmail account with 2-step verification vulnerable?

I can't believe it happened to me but I entered Gmail account's user-name and password into a website as part of a phishing scam. I use Gmail's 2-step verification and have changed my password. Is ...
12
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3answers
12k views

help understanding client certificate verification

I am creating an API that only certain computers should have access to. Communication will be via SSL between the server and the clients. In order to verify that a client has access, I would like to ...
12
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3answers
2k 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 ...
12
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1answer
858 views

Why is the truncate function for HMAC one time passwords so complicated?

I've been reading through RFC4226 as part of some research and I was wondering why the function to truncate the HMAC was so complicated. As far as I understand it, the last 4 bits of the HMAC define ...
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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 ...
12
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1answer
3k views

How will security need to be changed if P=NP?

If we suppose that it is found that P=NP, how will security measures need to be changed? I'd like to know the major security measures that are affected, and how they would need to be changed. We can ...
12
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3answers
434 views

Verifying server software integrity?

I'm trying to brainstorm a security scheme for the problem of verifying server software integrity. The domain of this problem is Game Servers built on Valve's Source Dedicated Servers. These servers ...
12
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1answer
1k views

Is Postgres's uuid_generate_v4 securely random?

I'm using Postgres's uuid_generate_v4 in a uuid primary key column to generate secure one-time authentication tokens. Is this okay? Does Postgres use a secure random number source for generating these ...
12
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2answers
318 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 ...
12
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4answers
2k 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 ...
12
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2answers
687 views

How do I prevent my twin sister's “pulled from public record” information from being used when I try to answer 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 ...
12
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3answers
591 views

Is it inconsistent to tell users to “not click on password links in email”, and requiring clicks on “forgot password” links?

On one hand, IT Security shops have been telling users to not click on links in email because they can do damage to your computer, or phish your personal information. Many of those issues are ...
12
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1answer
156 views

How can mobile sign-on be secured from imposter authentication screens?

History seems to have come almost full circle where old issues are shown in new/emerging technologies. Background If you trust the operating system, Windows originally had the Control - Alt - Delete ...
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1answer
1k views

MPPE-Send and Receive key derivation from MS-CHAPv2

I am trying to get the MS-MPPE-Send-key and MS-MPPE-Recv-key from the MS-CHAPv2 challenge material. I am able to follow the RFCs 2548 3078 and 3079 to the step of getting the GetNewKeyFromSHA() it is ...
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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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5answers
3k 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 ...
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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 ...
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3answers
1k views

Why is my phone connection secure without a password when WiFi is not even with a password?

When I talk on the phone or send text messages, I never need to type a userid and password. But when I use WiFi I need to use a password. How is the phone connection secured without a password, and ...
11
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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 ...
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5answers
4k 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 ...
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5answers
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Are case-insensitive passwords a bad idea?

I recently discovered a service where the password was not case sensitive. I understand basic principles of encryption and hashing so I am a bit worried, is this service storing my password in plain ...
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4answers
7k views

HTTP Basic auth password storage more secure than Digest auth

If you are using SSL already, it appears Basic auth is the way to go since you can perform bcrypt with the password when you store it in the database, where as Digest auth only allows md5. As we know, ...
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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 ...
11
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3answers
644 views

Security of pronounceable passwords

Some random password generators support the generation of pronounceable words of any given length n. Assuming that words are derived using 26 lowercase letters, the number of possible words of length ...
11
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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
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6answers
469 views

How to protect against adversaries snatching booted laptops to defeat full disk encryption?

I read an article describing how FBI agents snatched Ross Ulbricht's laptop while it was running to defeat full-disk encryption: Two plainclothes FBI agents, one male and one female, walked up ...
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4answers
716 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 ...
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3answers
1k 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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3answers
2k views

Length of CSRF Token

Is there any standard length of the token which should be used while generating the random tokens? Should we use the same standard which we use for generating Session IDs?
11
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4answers
10k 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. In the words of ...
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2answers
3k views

Benefits and drawbacks of giving an Administrator two accounts for elevated rights and another for daily use, such as email

Microsoft has long promoted the need to separate administrative accounts from regular use accounts, as shown with this guidance MSFT even went to far as create ADMINSDUser rights to put ...
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3answers
513 views

What email addresses are treated as trusted?

Windows Live recently suffered a security incident because they didn't realize that email addresses like administrator@live.fi are considered "trusted": some certificate authorities will consider ...
11
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1answer
870 views

How to stop password recovery attempts on accounts?

I am using social networking services such as My Banking GMail PayPal Facebook Twitter Google+ LinkedIn All of these services text messages me a six digit code to login from anywhere, even a ...
11
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1answer
458 views

Is TLS in Tor useless?

I am trying to optimize the Orchid Tor client library for my needs and noticed that every connection with every node uses TLS with turned off certificate verification. Actually there are no TLS ...
11
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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 ...
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5answers
3k views

Using Google Search results to determine password strength

Google is a repository of Internet data, as it indexes tremendous amount of data. It uses a prediction service to determine the rest of the search query. With such a huge repository in place, can we ...
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3answers
5k 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
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4answers
3k 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 ...