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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avoid hitting DB to authenticate a user on EVERY request in stateless web app architecture?

Summary Once a user logs into a web site and his username/password credentials are verified and an active session is established, is it possible to avoid hitting the DB for each and every request ...
23
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4answers
9k views

Are there technical disadvantages in using free ssl certificates?

Note this question is related, except this one is about free SSL certs. There are providers who are offering totally free entry-level SSL certs (like StartSSL). I was wondering if they are ...
20
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5answers
1k views

Why do some websites and programs restrict password characteristics?

There are some websites and even programs that I use that have rediculous password restrictions. Lots of forums for instance restrict passwords to ~32 characters. Others enforce a restricted charset. ...
15
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4answers
5k views

How to implement non-password authentication in a web site

In an answer to this question about pw reset, D.W. says: Lastly, consider non-password authentication. Passwords have many problems as an authentication mechanism, and you might consider other ...
14
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6answers
1k views

Is This Login Security Enough?

I'm coming up with my next login system for admins of an ecommerce website to have login form is SSL secured password is converted to sha256 before being transmitted (bcrypt is too slow still for ...
17
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4answers
13k views

why a client authentication is not commonly performed in the TLS protocol?

Is there any reason for this other than key/certificate management on the client-side?
10
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3answers
8k 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 ...
5
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6answers
908 views

How do I secure my login page?

The login page is the starting point to any web site and the most important thing to authenticate the user. When I begin to build any web application, I take a lot of time to think about how to ...
19
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4answers
1k views

Biometric versus other Two Factor Authentication Mechanisms

Over the years biometrics is the go-to movie authentication mechanism, but in the real world I'm getting conflicting opinions about it. Everything I've learned shows that biometrics are flawed ...
10
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4answers
3k 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 ...
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 ...
1
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3answers
5k views

What do I need to do to secure log-in and registration for my website?

What security features do I need to have in-place to ensure that my website log-in and registration forms are secure?
22
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5answers
7k views

Why is “something you know” the weakest factor of authentication?

Quoting from CompTIA Security+ guide The first factor of authentication (something you know, such as password or PIN) is the weakest factor. Why? it makes sense when we say that humans/users ...
11
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3answers
8k 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 ...
8
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6answers
737 views

Easy explanation of SSL client certificates for a developer

I've been thinking about using client certificates for my web apps, desperately hoping for security-conscious users to put their private key on HSMs so they don't get stolen even if the machine is ...
6
votes
3answers
29k 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 ...
4
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3answers
504 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 ...
19
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1answer
2k views

Is it secure to connect to a remote Windows Server using Remote Desktop only?

I have a Windows Server that I login to from my home. I only use the pre-installed Remote Desktop. Is this a secure way to remote login or should I improve it in some way? If I should improve it, ...
14
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5answers
2k views

What is the difference between login throttling and temporary account lockout? [closed]

I am currently working on the redesign of a login page. I have initially suggested that login be throttled whereby pauses (incremental - in number of seconds) are introduced between each failed login ...
14
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4answers
4k views

Three-Factor Authentication for Windows

This HowToGeek article... http://www.howtogeek.com/67556/how-to-unlock-your-pc-by-being-nearby-with-a-bluetooth-phone/ ...got me thinking. Is there any software (or combination of software) that ...
13
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3answers
12k 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 ...
12
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3answers
7k 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 ...
9
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2answers
4k 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 ...
7
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3answers
6k 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 ...
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 ...
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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1answer
5k views

How does a CSRF token prevent an attack, and how can I safely use/avoid it for my JSON API?

I'm trying to make an iOS app communicate with a Ruby on Rails website using JSON. While trying to post a login to create a user session, I discovered I was missing a CSRF token. I had no idea what ...
5
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3answers
7k 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 ...
4
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1answer
1k views

How secure is TOTP key on phones?

Our company is considering several options in moving to MFA with software OATH TOTP or yubikey OATH OTP. In regards to where the secret is stored, I'm aware that a yubikey or similar hardware device ...
18
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6answers
3k 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 ...
18
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3answers
27k views

What is single sign on versus federated login?

What is the difference between Federated Login and Single Sign On authentication methods?
16
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2answers
6k 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?
15
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5answers
975 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.) ...
10
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3answers
561 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 ...
8
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1answer
804 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
686 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 ...
8
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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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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 ...
12
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3answers
403 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
votes
4answers
869 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
votes
4answers
1k views

Is having the username and password fields on different pages more secure?

An online bank I use requires inputting your username, navigating to a second page and then entering the password to login. What actual security advantage does this provide, if any?
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
389 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 ...
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
1k 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
485 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
695 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 ...