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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47
votes
6answers
7k views

How do some sites (e.g. online banks) only ask for specific characters from a password without storing it as plaintext?

I thought How can a system enforce a minimum number of changed characters... would answer my question, but it seems this is a different case. When I sign on to my online banking account, I'm prompted ...
2
votes
5answers
167 views

Does publishing the md5sum of a private key compromise the private key in any meaningful way?

If I have a 4096 DSA private key used for signing binaries, and I want to ensure that a partner has an identical server using the same private key, can I send the md5sum of the private keys over an ...
35
votes
8answers
3k views

If I include a Forgot Password service, then what's the point of using a password?

I've implemented a Forgot Password service in the following way: User goes to login page, clicks on "Forgot password?" User is presented with a form that asks for their email address. Email is sent ...
0
votes
0answers
52 views

How are the sequence numbers generated in an 802.11 frame?

An 802.11 frame consists of sequence number in it. How are these sequence numbers generated? How random is it? Do these sequence numbers follow any particular pattern for the management frames in the ...
3
votes
5answers
3k views

Why is client-side hashing of a password so uncommon?

There are very few websites that hash the users password before submitting it to the server. Javascript doesnt even have support for SHA or other algorithms. But I can think of quite a few advantages, ...
1
vote
3answers
145 views

Will hashing passwords in my use case improve security and why?

I am developing an application the architecture of which is arranged as follows: Session host <---> Central relay server <---> Session client All communication between the initiating ...
2
votes
1answer
125 views

How safe is Two Factor Authentication (TOTP)?

If someone gets my phone and saves the values my authenticator generates, will that person be able to find out the shared key, which he/she will be able to generate codes himself/herself? If so, how ...
0
votes
1answer
43 views

Would Poly1305-PBKDF2 be secure

I have a Poly1305-implementation (not Poly1305-AES) in my library. The difference: Poly1305-AES uses a key and a nonce and then uses AES to generate a one-time-key from key + nonce. This is ...
-4
votes
2answers
98 views

Is there any benefit to login to a website as anonymously as possible, if you've already been there from an identifiable IP address?

Here's a basic example of the situation I am in: 1.Friend downloads full-length, new release movie on shady internet site (felony). 2.Uploads it to a randomly created, cloud hosting service account ...
6
votes
1answer
95 views

Does iPhone home button act as Secure Attention Key?

On an iPhone, does pressing the home button act as a Secure Attention Sequence? The home button is a physical button. You can press the home button whereever you are and go back to the home screen. ...
5
votes
8answers
714 views

Biometric authentication in the real world

can anyone give a realistic estimation, based on real-world experience, of how much biometric authentication techniques are being used in the IT field?
3
votes
5answers
912 views

If someone steals my laptop while I'm logged in, how can I protect my browser?

My question has its roots in an xkcd from this week: http://xkcd.com/1200/ Isn't this true and ironic? We place so much emphasis on browser security and OS security -- and rightly so -- yet if I ...
4
votes
0answers
97 views

Deal with number changes in a phone number based authentication/login system

Twitter Digits (https://get.fabric.io/digits) provides an authentication/login system based on phone numbers for mobile apps, and several other mobile apps (e.g. Square Cash, ...
25
votes
4answers
2k views

Why do some sites block pasting into username or password input fields?

I use a few websites that prevent me from copying & pasting into the username or password fields. It's quite frustrating when using a password manager, and if anything I'd think it discourages ...
2
votes
2answers
187 views

token based authentication attacks

JSON Web Token seems to be a very good tool to authenticate users. But I wonder if an attacker can take the token used by another user and use it for his own attacks. And to be more precise what makes ...
42
votes
7answers
9k 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? ...
3
votes
7answers
364 views

Why not ask for a password and 2-factor token at the same time?

I have observed a number of web-based login forms that offer 2-factor authentication do token entry on a second form after validating your username and password. Is there a reason not to ask people ...
3
votes
3answers
221 views

What are the (practical) dangers of writing your own login method?

I have always been told that writing your own login method (e.g. validate user given the username and password) is bad practice, and that one should reuse existing libraries for that. I have always ...
1
vote
3answers
98 views

Securing a secondary login page for inputting a multi-factor auth token

I would like to implement the following use case: User lands on the login page User submits login credentials Credentials are validated and they are redirected to another page for inputting the ...
0
votes
2answers
579 views

Generating authentication token from PHP sessions

I have a traditional PHP site which uses sessions. I've developed a real-time app in nodejs and wish to authenticate users here based on their PHP session. The procedure would go something like this: ...
5
votes
3answers
401 views

Authenticating client without hardcoding key?

A basic question, but I'm not a master and this is puzzling me- How is it possible to authenticate a client from the server's perspective? i.e. imagine you're the server, and you want to give the ...
1
vote
1answer
55 views

Best practices for encryption from web<-> specific client

If we want to allow sensitive data between a web server and specific client only, is there anything more that can be done besides the following? Note that this is potentially a duplicate of ...
20
votes
2answers
14k views

Difference Between OAUTH, OpenID and OPENID Connect in very simple term?

I am very confused the difficult jargon available in web about OAUTH, OpenID and OPENID Connect. Can anyone tell me the difference in simple words.
3
votes
1answer
82 views

Mobile authentication with password as param in get request over ssl

I'm building out a new services layer for an existing mobile application. The mobile application authenticates with the existing services layer by providing the user name and password as url params in ...
2
votes
1answer
42 views

Choosing a group of symbols that contains a password

My bank employs a step in its authentication process besides [the card itself and] the regular password, where the user has a secondary password (3 small sequences of letters, such as Hy X Ba) ...
-7
votes
1answer
138 views

How to attack on a web page to gain username and password? [closed]

In a situation where a web page is not using SSL and someone wants to attack to gain the username and password. How it can be done? Given the situations: Passwords are not stored in plain text. ...
2
votes
1answer
52 views

How to verify installed packages [closed]

On Linux (Debian x64) I recently installed some software with: apt-get install the_package_name APT told me some packages couldn't be authenticated but I ignored the warning and installed anyway. ...
1
vote
0answers
45 views

If I have the cell #. switch ID and name, can I locate an physical address? [closed]

Only a PRO can help me! My husband had an affair, said it was over five years ago and I should not be concerned, ever again. Yet, the result was devastating, medically with cancer. I believe people ...
1
vote
1answer
4k views

SAML and kerberos what to use where [closed]

I came across SAML and kerberos, both are used to establish identity using assertions (tickets) so is there an overlap in their use ? Can somebody highlight their differences and point which ...
9
votes
1answer
623 views

Should I use a Certificate Revocation List?

I've been trying to provide security to my API. I will issue certificates to my clients to access my API through a TLS channel. So it'll be a SSL-Client Authentication. I'm wondering, should I use ...
20
votes
3answers
7k views

Should we store accesstoken in our database for oauth2?

I have a requirement to implement Facebook and Google login in my web application. I also need to access a user's Facebook/Google+ friend list. I have gone through the complete OAuth2 documentation of ...
2
votes
1answer
94 views

Protecting a statistics endpoint

When we download an application - it asks us whether it's ok to submit statistics, error reports to the vendor. Since this data is sent from the application to server endpoint - I am wondering how ...
11
votes
3answers
12k 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 ...
3
votes
1answer
3k views

Token authentication and storage / websocket issues

My application is running an API authentication that uses tokens rather than cookies. This leads me to ask a few questions : What is the most secure way to store the token ? By using random ...
1
vote
1answer
200 views

Password-less authentication in web apps - How safe it is?

I read a long time ago this article about how could work a Password-less Authentication System, which sounded to me like a great idea. I even built it in a small fun little application for fun. To ...
3
votes
4answers
256 views

How do clients enroll using SRP?

From what I understand, one of the benefits or Secure Remote Password (SRP) is that is does not require reliance on certificate authorities. In a scenario where clients need the ability to register as ...
2
votes
1answer
57 views

Using Google Authenticator for SSH sessions

So I have an SSH tunnel which I use with dynamic port forwarding to the alternate http port on the client. For initializing this connection, I'd like to implement an additional verification step, ...
2
votes
1answer
162 views

How to view all SSH authorized_keys for a unix server

How would I view all the authorised SSH clients from a unix server? I know that cat ~/.ssh/authorized_keys shows authorised keys if logged in from root. Can other users set their own authorised keys ...
20
votes
4answers
2k views

Effectiveness of Security Images

Do security images such as those presented upon logging into banks provide any tangible security benefits, or are they mostly theater? Per my understanding, if somebody is phishing your users, it's ...
2
votes
2answers
111 views

Single-use password as the default authentication method?

The crazy password requirements (joke1, joke2) lead me to a situation where there is no way for me to memorize the passwords to the several sites that make those requirements. The result is that ...
3
votes
1answer
111 views

Client Certificates

After countless hours of reading I have come to the find that mutual authentication via client certificates seemed to be a viable and appropriate solution for the following scenario. I have a ...
2
votes
1answer
38 views

Is this system of authentication secure for a mobile app? What can I do to improve it?

Users authenticate with their phone number, get a pin text, and if it is correct, they get an access token. Store the access token in a DB in a Token model. The client always sends the access token in ...
4
votes
2answers
1k views

Is secure web-app off-line auth possible?

I'm currently thinking about a web-app that can go offline (after being online) and still be able to provide authentication to the user securely. (For example, in a multiuser environment, it's quite ...
6
votes
4answers
415 views

Establishing a Reputable Pseudonym with PGP Key

This has become a bit of a thought experiment for me. Suppose someone would like to establish a pseudonym along with a corresponding PGP Key, how could other people verify the correspondence between ...
11
votes
7answers
2k 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 ...
0
votes
1answer
300 views

How can I handle user authentication and sessions in my app?

I'm currently building an authentication module and I've got a question. I have set up a server with an API and want my users to authenticate to this server, but I use AngularJS for the site. ...
1
vote
0answers
50 views

Oauth authentication without state parameter

I have some security concerns about the first step of account authentication in my application. The authentication goes through an OpenID provider. If the response of such provider shows that the ...
1
vote
2answers
1k views

Could “receive SMS online” site be a scam?

There is a site that allows you to see all SMS received by a certain set of phone numbers (owned by the site). This seems to be meant for services that require two-factor authentication using SMS, ...
5
votes
2answers
484 views

Should email verification be followed by password-based login? Why?

[This is a duplicate, considered off-topic at http://stackoverflow.com/questions/26564992/should-email-verification-be-followed-by-password-based-login-why] A typical account creation process seems ...
3
votes
2answers
611 views

How to use TPM to perform platform authentication?

I am currently looking at TPM (Trusted Platform Module) and wondering how does TPM offer platform authentication. Suppose a legal host is deployed on the cloud. How do I use TPM to assure that the ...