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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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 ...
9
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2answers
3k 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 ...
8
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3answers
2k views

Is it possible to use a GPG or SSH key for web based authentication in a secure fashion?

Let's say hypothetically I am writing a web application targeting technically inclined, security-conscious users who have no problems generating and using GPG or SSH keys. Is it possible to use said ...
7
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3answers
2k views

Is my session-less authentication system secure?

So, I've created an authentication system. Poured over it for any kind of security flaws and tested the crap out of it. I think it's fairly secure, but there is one "different" by-design aspect of it ...
5
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3answers
6k views

How to distribute client certificates without exposing private key?

I'm desgining a B2B web service based on WCF. As the number of clients is relatively small and security is a priority, i have chosen to go with X509 client certificates for client authentication. I'm ...
3
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3answers
404 views

Can a zero knowledge proof of voting be made using a trusted auth server (without client side crypto)?

Questions: Can one implement a secure voting system having all the features described below? e.g. without disclosing any individual's vote to the government server (or the third party), preserving ...
18
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6answers
2k views

Why do we ask for a user's existing password when changing their password?

In a web applications context, when a user wants to change their current password, generally they would have to enter their current password first. However at this point, the user has already been ...
15
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3answers
21k views

What is single sign on versus federated login?

What is the difference between Federated Login and Single Sign On authentication methods?
15
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5answers
881 views

Safe way to authenticate (multi-factor authentication?) while being monitored?

(I'm trying for a bit more precise answer, particularly with regard to multi-factor authentication, than I received for "Safe way to use a computer that has spyware/keylogger installed?" on SU.) ...
13
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2answers
5k 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
459 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
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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 ...
9
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3answers
9k views

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 ...
8
votes
1answer
626 views

Build a secure channel without SSL/TLS

I'm looking at possible options to build a secure channel between multiple embedded devices with limited cryptography capabilities and an HTTP server (It could be some sort of web service). 1. ...
8
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2answers
590 views

How is an HTTPS login secure when pages use HTTP?

When someone go to eBay's website, they use an unencrypted connection between their PC and eBay's server. If they sign in, they are redirected to a secure site identified by its certificate and may ...
7
votes
3answers
5k views

Terminology: authentication vs verification

The two words have a similar meaning and I'm having difficulty adequately explaining the difference to someone. You verify a person's identity by having them show a form of identification, such as a ...
6
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4answers
4k views

HMAC/PBKDF2 vs Simple hashing algorithm for web service authentication?

We are in the process of creating a web service and have been investigating ways of securing it. In reality, the service is likely to get very little traffic and the data is likely to be of little use ...
5
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3answers
25k views

Four-way Handshake in WPA-Personal (WPA-PSK)

Can someone explain to me in what consists the Four-way Handshake in WPA-Personal (WPA with Pre-Shared Key), which informations are being sent between AP and client, how is it possible to find the AP ...
5
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2answers
3k views

Dealing with expired or revoked signing certificates with Infopath documents

Suppose I have an Infopath form that is digitally signed today by a valid, and active user. When that user leaves the company, we disable the account and revoke the certificate. This causes a problem ...
16
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5answers
2k views

How many Stack Exchange logins should I have?

On Stack Exchange's Add a login page, one can add logins with Google, Facebook, Yahoo, etc. How many logins should I have to provide the least chance of a hacker gaining access to my Stack Exchange ...
15
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3answers
2k views

Multi-tenancy, SSL Certificates, and Subject Alternative Name

The X509 specification allows a CA to issue a single certificate for multiple hostnames, by using the "Subject Alternative Name" extension. From the spec: The subject alternative name ...
13
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5answers
1k views

Is there any reason to show the same message for invalid username as password?

I've seen a security question/requirement that a website login return the same error message for invalid password as for non-existent user. The idea being that this it makes it impossible to discover ...
12
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3answers
359 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 ...
10
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4answers
824 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 ...
9
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3answers
6k 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 ...
7
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4answers
357 views

Candidate authentication in large scale assessment

First of all, I'd like to apologize beforehand if the questions I am about to ask are not really suitable for this site. I could not think of any other category to post under. Right, here goes. We're ...
6
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2answers
1k views

How do I log everything a certain program is doing?

i have a program which is pretty simple. Its just a simple login form. Is there any possibility to log what this program is doing (maybe which file he is accessing and which website he is visiting ...
5
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1answer
1k views

Is this admin area secure enough? V2

This is a response to my previous question, Is this admin area secure enough?. There were some very helpful answers there, for which I am very grateful. So I went back to the drawing board and here ...
5
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3answers
900 views

Is it possible to have authentication without state

In order to login to most websites you need a username and password which is often stored in a SQL database. You are storing per-user information that can change, this is state. Can you prove that ...
4
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1answer
266 views

Securing server to server http communication

We are trying to come up with a scheme to secure http communication between our internal servers. Are there any good established schemes out there? The requirements we have are: The clients and ...
4
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2answers
620 views

user authentication by decrypting a random blob

Normal user authentication is done by comparing "hash"-values. A simple example of this: The user password is hashed with PBKDF2 on the client using a salt (the salt is the hash of the user password ...
4
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3answers
6k views

Do you need to encrypt session data?

I came across a session management class in PHP which encrypts session data in the session storage folder (i.e., /tmp) and can be decrypted later in your script using a key. I was wondering if it's ...
4
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2answers
536 views

intrusion detection on own hotspot?

Is it possible to detect failed logins on the hotspots you create with your windows/linux laptops? So you can detect some dumb brute force/guessing attempts? For example, a log like this: TIME DATA - ...
9
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3answers
400 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 ...
9
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1answer
56k 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
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2answers
871 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 ...
8
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4answers
4k views

Is it okay for API secret to be stored in plain text or decrypt-able?

Aren't API keys considered usernames and API secrets considered passwords? Why is it that API servers like Amazon Web Services allow you to view your API secret in plain text? It makes me think they ...
8
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3answers
637 views

Which authentication at the end of the Secure Remote Password protocol?

For the the client and server to prove to each other that they have the same premaster shared key, the original author suggests this: M = H(A | B | K) --> <-- H(A | M | K) ...
8
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2answers
464 views

How do you Secure VOIP in a large organization

As part of a large organization looking to implement VoIP, to get on the bandwagon of savings and converged network focus, I'm being asked to look at the security concerns to develop a policy to help ...
6
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1answer
702 views

What's keeping a malicious man in the middle server from forging a valid certificate

According to process of authenticating a server certificate: What's keeping a malicious server to fill up a valid server certificate since it knows all the things: Forged Server public key (man ...
6
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3answers
858 views

Attack vectors for brute-forcing website passwords

When talking about password security, a lot of discussion centers on the risk of a password being guessed in a brute-force attack. For websites where a user has registered an account, what are the ...
5
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1answer
1k views

Hotspot with same SSID, how does authorization work?

My university has a wireless network I log into with my username and password. It's using PEAP. My phone and laptop automatically connect to this SSID when they detect the network. If someone sets up ...
5
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1answer
3k views

WCF - Is this a good security Architecture?

I am building an information recording system (WCF based) for a business that is accessible by staff over the internet. This software will not be distributed and there will only be a handful of users ...
5
votes
2answers
997 views

How to login and encrypt data with the same password/key

I've made a "vault" web app in PHP for storing passwords, credit card numbers, etc. It's mostly just for myself, but I'm practicing building it with multiple users in mind. I use two way encryption to ...
5
votes
2answers
185 views

What are the risk tradeoffs of all-in-one “smart” IDs vs. using a separate hardware authenticator?

In many organizations these days, employee IDs are very mutli-functional. They can serve as: Visual identitiy verification. (Including employee photo, name, ID number, and other details on the ...
5
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3answers
1k views

What authentication system (OpenID, Facebook, etc) permits Javascript-free and/or Cookie-Free operation?

I'm looking for an authentication system that relies on 3rd parties (ADFS, OpenID, SAML) but doesn't rely on cookies or Javascript... or at least can make them optional. My intent is to gracefully ...
4
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3answers
559 views

How can I verify the identity of a US | UK -based person and prevent *fake identities* from being accepted?

Given that it's possible to fake ID cards and fake social security numbers are created, I need to ensure that all users of my site are US or UK based citizens, and don't have more than one account. A ...
4
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3answers
449 views

Is this admin area secure enough?

EDIT: Please view the revised question instead The admin area has special access to the database (modifying orders, etc). To help explain, I drew a diagram, so here is my process: Notes: I ...
3
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1answer
127 views

Login to one site using other site's credentials

I am frequently seeing websites that allows a user to log-in to their site using other websites log-on credentials. If there is a page that allows me to log-in using my google account or facebook ...
3
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2answers
217 views

What's a good time period before refreshing CSRF token of the user session?

I am using a form token to prevent CSRF attacks. Those tokens are stored and tied to a user's session. Now I want to refresh the token only every N minutes or hours so that the user's don't experience ...