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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3
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2answers
758 views

User authentication + database encryption with same password

I'm working on a private project where I need to store a users financial data in a database. I'll encrypt this data using AES, and I'll be using scrypt to generate a AES ecnryption key from a more ...
2
votes
1answer
184 views

Why recommend “letters, numbers, and special characters” in a User ID?

Why do some sites recommend "letters, numbers, and special characters" in a username or User ID? When creating a User ID at the www.discovercard.com website, the "User ID Strength" indicator meter ...
16
votes
7answers
1k views

Taking password letters not whole one, is this secure? [duplicate]

I found a site which is taking password letters from their users not the whole password. Is this secure? Or do they have saved password as salted hash (MD5)?
7
votes
4answers
1k views

How to prove Bob has received Alice message

I have read up on Digital signature and it is stated that it provides non-repudation. Assuming Alice signs the message using her private key and sends it to Bob, Bob can use Alice's public key to ...
7
votes
3answers
533 views

Does Gmail 2-factor auth increase security on smartphones?

So I have enabled 2-factor authentication on Gmail, which means that if I log in on a new machine, it sends a token to my phone. Now, if I access Gmail from my phone, it seems like I have only one ...
7
votes
1answer
3k views

Does NIST really recommend PBKDF2 for password hashing?

We hesitated between BCrypt and PBKDF2 for password hashing. In many forums and blogs people say something like "In their Special Publication SP 800-132 NIST basically recommends using PBKDF2 for ...
7
votes
2answers
2k views

ssh public/private key pair

I am having problems understanding how ssh really works. I know it uses a public key cryptography to encrypt messages. However, I can ssh to a server without first generating a public/private key pair ...
6
votes
5answers
688 views

Should a closed source website keep a secret key in its source?

Various APIs (such as Facebook or Amazon S3) require a secret key to authenticate access to the service. Obviously, if source code is public, the key should not be in the source! What about for a ...
2
votes
7answers
447 views

Is it wrong to root login with SSH?

I've long been under the impression that with unix, you should never login as root. Now I've started using Virtual Private Servers over at DigitalOcean, and some advice is to use SSH keys to login as ...
2
votes
3answers
3k views

Dealing with untrusted administrators in a Windows domain

I'm providing consultation to a company, where they have domain-joined Windows workstations. One basic requirement is that they don't want anyone (including the an administrator) to be able to login ...
1
vote
2answers
562 views

Determining the accuracy of a biometric system

How is the accuracy of a biometric security system (its ability to minimize false acceptance rate and false rejection rate) determined?
10
votes
4answers
6k 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 ...
8
votes
2answers
2k 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 ...
8
votes
4answers
2k views

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 ...
6
votes
2answers
853 views

Storing third-party auth info securely

Suppose there's a multi-user web application that requires access to user's mailbox (on third-party service, like gmail, etc.). This access needs to be persistent. Which means we'd have to store user ...
5
votes
2answers
4k views

When using symmetric key encryption, do we need to sign?

Say we're using a shared key between two parties, that has been distributed using public key encryption, is it still necessary to sign any data that's encrypted using the shared key? Or is it enough ...
5
votes
3answers
1k views

storing the third party credentials in the database/some secure place

This question is about storing the third party credentials in the database/some secure place so that it can not be accessed by only authorized user. Our system connect to the third party system using ...
4
votes
2answers
946 views

Is HTTP Digest + MD5 still an alternative to consume my own api?

I'm reading a lot about implementing security constraints to a REST API. There are a lot of methods, some better than others for 3party applications or to consume my own API. HTTP Basic + TLS (with ...
3
votes
2answers
201 views

How does my bank knows my second and forth chars of my password [duplicate]

I see that the new login mechanism used by some banks in UK and also used by visa debit authentication is to ask for three random characters from your password at login (for example second, ninth and ...
1
vote
3answers
285 views

Should I trust my bank after this [closed]

I have just discovered that I can login to my bank with passwords that is not mine. Example: My password is "1234" but I am authorized with all possible post characters. For example "12345" or ...
1
vote
3answers
221 views

Are subdomains a cure for phishing?

Seeing as phishing is getting more popular and users are becoming less concerned about security, I am trying to come up with a solution for a new site of mine that can stop phishers. For instance, any ...
1
vote
1answer
215 views

Securing communication

The problem: I have an open-source client (a Firefox add-on written in JavaScript) and a server containing somewhat sensible user information: username and user history (all from YouTube). The client ...
0
votes
2answers
255 views

Security concern to implement a web based remote desktop

I am implementing a web based remote desktop application.Through this application client can connect to the server and can access the server using JSP/Servlet Java robot class. I can configure the ...
42
votes
5answers
7k views

What are the downsides of BrowserID/Persona compared to OpenID/OAuth/Facebook?

Mozilla went live with a new service called BrowserID/Persona (announcement, background). It is intended to replace current single-sign-on solutions such as OpenID, OAuth and Facebook. One advantage ...
57
votes
6answers
7k views

Four-factor authentication

I'm sure you've all heard of two-factor/multi-factor authentication. Basically it comes down to these factors: Knowledge - something you know (e.g. password, PIN, pattern) Possession - something you ...
21
votes
3answers
5k views

What are the main advantages and disadvantages of webid compared to browserid?

What are the main advantages and disadvantages of webid compared to browserid? This question is inspired by this answer which got a number of upvotes despite being very vague on the topic of that ...
40
votes
6answers
6k views

Is using a public-key for logging in to SSH any better than saving a password?

Using a public/private key pair is fairly convenient for logging in to frequented hosts, but if I'm using a key pair with no password, is that any safer (or less safe) than a password? The security ...
37
votes
4answers
10k views

How secure are the FIDO U2F tokens

Google and Yubico just announced the availability of cryptographic security tokens following the FIDO U2F specification. Is this just another 2FA option, or is this significantly better than solutions ...
23
votes
4answers
2k views

Disclose to user if account exists?

Someone told me it shouldn't be possible for someone to detect if a certain email address is a registered user on a Website. So, for instance, when the user asks to reset his password, you should say ...
39
votes
6answers
2k views

Is the concept of Authenticated Anonymity possible?

Or is authentication essentially incompatible with anonymity? If we have the idea that authentication is proving that someone is who they say they are and anonymity is essentially having an unknown ...
33
votes
9answers
2k views

Use additional “password” in Referer to hide private site?

I have a private (= I'm the only user) site at example.com/private/. Nothing else is published at this host (it's my domain). I don't want anyone to know that there is anything at example.com, ...
54
votes
12answers
3k views

How do you log in from an unsecured computer?

Suppose that you are on a cybercafe, at a friend's home or at your work office, and you need to log in on a site, but you feel that the the computer can not be trusted (e.g. your friend isn't ...
19
votes
1answer
123k views

How do I clear cached credentials from my Windows Profile?

Windows seems to be saving my credentials for a variety of applications (terminal servers, etc) and I'd like to purge this data. How can I backup and purge this data?
42
votes
7answers
8k views

Should I change the default SSH port on linux servers?

Is there any advantage in changing the SSH port, I've seen people do that, but I can't seem to find the reason why. If you have a strong password and/or a certificate, is it useful for anything? ...
19
votes
5answers
1k views

Good session practices

What are some good practices for ensuring logins, session IDs and session content are secure for a website?
22
votes
3answers
9k 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 ...
21
votes
4answers
8k 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 ...
11
votes
4answers
5k views

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 ...
20
votes
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
votes
4answers
4k 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
votes
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 ...
5
votes
6answers
807 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
votes
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 ...
16
votes
4answers
11k 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?
12
votes
3answers
477 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 ...
9
votes
3answers
7k 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 ...
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 ...
10
votes
4answers
2k 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
3answers
7k 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 ...
1
vote
3answers
4k 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?