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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Secure communication between applications using SSL Certificates

I am looking for a way how to secure communication between our applications. There is a "server" application listening on some TCP port and "client" application which is communicating with the ...
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439 views

How to protect against login CSRF?

http://seclab.stanford.edu/websec/csrf/csrf.pdf points out that most CSRF protection mechanisms fail to protect login forms. As http://stackoverflow.com/a/15350123/14731 explains: The ...
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305 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) ...
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9k 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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238 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 ...
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3answers
919 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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956 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 ...
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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 ...
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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 ...
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571 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 ...
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359 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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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 ...
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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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7answers
451 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 ...
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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 ...
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4answers
10k 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 ...
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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 ...
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11k views

How does ssh public key authentication work?

My basic understanding is this: The (connected to) server's sshd uses the public key to encrypt some message The client's ssh or ssh-agent decrypts it and sends something back (the message's ...
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759 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? ...
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243 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.) ...
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540 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 ...
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4answers
431 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
905 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 ...
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845 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?
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1answer
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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 ...
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452 views

Are there any smartcard/hardware-tokens for certificate-based authentication which are easily destroyed?

It's all very well to use multi-factor authentication, but supposing you want to 'destroy a factor' so that in an situation where you are likely to be coerced to provide your passphrase, you can ...
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263 views

What shell binary should I use for the root account on a Linux system?

Is there a security advantage to using a different shell for the root account, either a hardened shell program, or simply a shell binary stored in a non-standard location?
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If I am obliged to store a password/certificate on a client side, how can i make sure that it is protected?

In certain cases we need to establish a key/password/certificate as a first timer and then as a client we need to use this key/password/certificate to get authenticated. Therefore the ...
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328 views

Optimal variable sizes in the Secure Remote Password protocol

I am implementing the Secure Remote Password protocol: U = <username> --> <-- s = <salt from passwd file> a = random() A = g^a ...
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3answers
794 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 ...
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Keeping user session alive - security considerations

We have recently developed some functionality for our web app to allow a user to remain logged in indefinitely, and are interested in knowing the security ramifications of doing so. The goal of this ...
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382 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 ...
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5answers
388 views

Oldest security feature still in active use

Beyond commonsense and physical access controls, is the system password the oldest still in active use security feature? By physical access, I mean for example leaving the system within a secure ...
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Aren't permanantly logged in accounts inherently insecure?

The basic premise behind a "keep me logged in until I log out" feature is a cookie is stored with some identifier that is used to log the user in again when returning to the site. While these ...
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Is there any SQL injection for this PHP login example?

I want to write a login form, and I got one example from the web. I want to know, if there is any SQL injection for this code? If there is, what could the exploit's web form entry look like? This is ...
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How to verify new accounts against a known persons database?

I need to (try to) solve the problem of new account creation for a patient portal for a medical records system (electronic health record). That is, a way to activate a patient online and match her ...
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3answers
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What common products use Public-key cryptography?

I want know what common use products are there that use public key/private key cryptography?
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How to protect ftp account information in the source code of a program

I wrote a game which stores high score information on an ftp server. In the the source code I need to write out the ftp link with the account name and password in it. For example: url = new ...
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3answers
487 views

Why would a website allow answers to security questions to be used interchangeably?

I needed to reset my password on a website that uses security questions for the purpose, and I noticed something strange. My hypothetical security questions are (not the ones I actually use) are: ...
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4answers
632 views

Is using a flash drive as a base for security a safe thing to do?

I'm developing some software for schools. I've found severe flaws with the current popular school LAN protection that I feel needs fixing so I plan on releasing my own software. One the those ...
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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 ...
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What is single sign on versus federated login?

What is the difference between Federated Login and Single Sign On authentication methods?
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2answers
523 views

Is a rand from glibc's rand secure for a login key?

Same question as Is a rand from /dev/urandom secure for a login key, but with glibc's rand function instead of /dev/urandom. And what would be a sufficiently secure seed generator?
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6answers
602 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 ...
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3answers
887 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 ...
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zero knowledge proof and its protocol

In Zero-Knowledge Proof where we take the analogy of Peggy (Prover) and Victor (Verifier): In this story, Peggy has uncovered the secret word used to open a magic door in a cave. The cave is ...
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iPhone 5S security: Given someone's fingerprint can I use a 3D printer to create a fake finger with a real fingerprint on it?

With such a big deal being made about the iPhone 5S's fingerprint reader (and formerly the Thinkpads' fingerprint readers) I really wonder how secure it is to use fingerprints in lieu of passwords. ...
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Choosing a session ID algorithm for a client-server relationship

I am developing an application which has a client-server relationship, and I am having trouble deciding on the algorithm by which the session identifier is determined. My goal is to restrict ...
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How do RSA fingerprints protect from MITM attacks?

I understand that RSA fingerprints are used to verify that you are really connecting directly to who you want to connect to, and not someone else posing as that site. Like when you do a git push, it ...
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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, ...