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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1answer
158 views

How can I successfully perform an xss attack on a dummy website? [closed]

in my security course, we were told to practice an xss attack using firefox on this website; http://permalink.co/ No worries, this is a website specifically setup for us to practice ...
3
votes
2answers
124 views

Is there any point in using two step authentication if you have strong passwords?

If you are in the habit of using strong passwords (randomly generated by password manager) is there any point in using two step authentication? Assuming that 99% of the time that when you enter a ...
3
votes
2answers
110 views

Why would you decouple your resource and login servers?

As described on this link, OAuth specifies that a login server and a resource server should be decoupled. The idea is that if one of your resource servers gets hacked, no password data is lost. All ...
2
votes
1answer
130 views

Smart lock protocol

I made an Arduino project to lock and unlock my door via my phone (with Bluetooth). It works well but it’s unsafe since I just send the lock and unlock command in cleartext, without authentication or ...
0
votes
1answer
53 views

MD5 before PBKDF2 on legacy software

I am mantaining a legacy software that uses MD5 in the following way: The client asks for a 16 byte salt when authenticating an account. The server generates a 16 byte salt, links it to the account ...
0
votes
1answer
91 views

Security tradeoffs while designing a mobile Web Service API

I'm not a security expert but I want to ask about tradeoffs in a web service API I'm designing for mobile apps. It is an API which tracks users' locations so yes, the data is reasonably sensitive. ...
0
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0answers
18 views

Difference between Kerberos and GDOI

What is the difference between Kerberos and GDOI, I know first is more toward authentication and latter is more toward multicast key management, can I use Kerberose protocol in GDOI for server and ...
0
votes
0answers
21 views

Difference between Kerberos and GDOI?

What is the difference between Kerberos and GDOI, I know first is more toward authentication and latter is more toward multicast key management, can I use Kerberose protocol in GDOI for server and ...
1
vote
1answer
672 views

Untrusted connection visiting https://www.opensource.apple.com/

Somebody on Stackoverflow posted some code from https://www.opensource.apple.com/ When I click this link in Firefox (36.0) it says "This Connection is Untrusted". But other people on that thread on ...
1
vote
1answer
59 views

Why should I include a client_id in an OAUTHv2 password grant request?

Like little red riding hood, you don't know who is knocking on the door... Why even bother accepting a client_id in case of a API <-> Javascript-website or API <-> Android App password grant ...
1
vote
1answer
75 views

Limiting Login Attempts [duplicate]

I have to set up a server that will allow remote logins. Obviously security is an issue. In this first pass we are discussing:- Locking a person for 15 minutes if they fail to login correctly three ...
1
vote
1answer
51 views

Using a Cryptovariable with an API Designed for Human-Generated Passwords

I'm working with a vendor who provides an API with a user registration method clearly designed for human-generated passwords. We're calling the API in an offline server-to-server fashion, however, ...
0
votes
1answer
73 views

Why first kerberos message is not ciphered

When analysing Kerberos exchange (and other similars as Needham, Denning, etc.) I wonder why the first message where the identities of the client and remote are not encrypted. In case not encrypted I ...
1
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1answer
62 views

Retrieve anonymous credentials

Background A registration process to acquire an anonymous, verified account goes like this: Registrant provides proof of individuality to a Registrar. Registrar verifies proof, ensures no prior ...
2
votes
0answers
369 views

JSON Web Tokens vs. SAML

I don't know too much about security. Specifically, I don't understand the difference between JSON Web Tokens, SAML and OAuth 2. If you could provide some pointers and high level overview of their ...
3
votes
3answers
161 views

Acceptably secure solution for users to log in with a short unique code only (no username)

I am creating a website whereby users are given an account by invitation only, and are sent a unique code by post. Users can then log in (at least the first time) by entering the code only. The goal ...
3
votes
1answer
83 views

Challenge Response with a Tan Book?

i am trying to secure a connection between a Mobile Device (Client) using a webApp and a Home Device (Server) in a potentially unsafe Wifi Network. The communication is asynchronous and i am trying ...
2
votes
1answer
79 views

How do Client-specific keys and Certificates work?

I have clients that communicates with my server. Clients sends it unique id (guid) to server with its request over a secure https channel. Also to increase security I use my own private-public key ...
2
votes
1answer
78 views

Is TLS enough to prevent eavesdropping? [duplicate]

Is it enough to use only SSL/TLS for client-server application with authentication, registration and data transmission (like chat)? If it is not what I also need to use?
1
vote
2answers
94 views

Circumventing disadvantage of IP-based account lockout

So we're trying to prevent brute-force attacks on our web server login page--currently we just do IP-based locking if x failed attempts from IP address Y occur over z time period. After a security ...
0
votes
0answers
81 views

How to associate an oAuth token with a particular user. Is this possible?

We have HTTP Rest services and SignalR (aka Web sockets, server send events, etc) for cases in which we need to push data from the server to the Web UI . We are currently using the built in tools that ...
4
votes
2answers
80 views

FIDO: what is the benefit of the challenge parameter?

In the enrollment stage an attacker could intercept the message and answer with a signature based on the correct challenge. I know that normally you include a symmetric secret in such a challenge, but ...
1
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0answers
39 views

authentication token not stored in DB

I am implementing a webserver and the guideline I am following suggests: - to create token by a Serializer that takes the IdUser, a symmetric key and an expiry date - provide it to the user but not ...
1
vote
0answers
107 views

Is generating custom authentication token for WCF service requests a good practice?

I have public WCF web service which works over https. There are lots of technical restrictions on client side, so I can't use any advanced schemes like oauth. I have registered users and some of them ...
0
votes
0answers
40 views

Additional security for services hosted on a 2FA or Multi-Factor Authenticated Network

I am aiming to lock down a web service that accesses other services and has a publicly facing UI. I have a hosted service on a network that requires 2-factor authentication to access. This service's ...
3
votes
1answer
67 views

Is it possible to restrict a client-side certificate (for web auth) valid only for a given site name?

If I have 2 websites, a.example.com and b.example.com. Those sites use TLS and SNI, and require client authentication with certificates created with my own CA. The use case is that some clients have ...
1
vote
1answer
107 views

How do MACs provide authenticity?

I don't see how they're different then hash functions. Couldn't Alice use Bob's key to produce a MAC and send the message to Jim.
93
votes
17answers
23k views

Is “password knocking” a good idea?

With port knocking, you have to "knock" on specific ports in defined order to expose a port on which service is running. How about password knocking? For example you have three passwords: A, B and C. ...
0
votes
1answer
123 views

Can Google's administrators be trusted with Google Authenticator? [duplicate]

Suppose there is an evil Google administrator who has full access to every server or network at Google. Will such a person be able to abuse the Google Authenticator technology to gain access to ...
0
votes
1answer
68 views

How Google Authenticator in Android mobile identifies this is the right SSH server?

I am new to Google Authenticator mechanism. I gone the basics of mechanism but I couldn't understood what logic behind that to make a connection to the Linux machine. I have a Linux which have no ...
0
votes
1answer
196 views

Drawbacks of using ADFS for SSO for external users

Is there any drawback for creating a separate AD forest for external users of organization to authenticate them to access some web applications? Is there any performance and synchronization issues ...
5
votes
2answers
135 views

Four eyes authentication for command execution on Linux. (OS level) [closed]

I reached the end of the internet with no success, so now I turn to you guys. What I'm after is a way to implement four eyes principle on the OS level for certain commands in Linux. Example : The ...
3
votes
0answers
296 views

Social Login + OAuth2-secured REST API

I'm implementing social login with Facebook, Twitter and Google+ on our OAuth2-secured REST API (secured using spring-security-oauth). I'd like to make sure that the following flow is secure and that ...
3
votes
1answer
246 views

Best practices for passwords on registration?

I have a website which users register an account. On the registration field, the form fields are: Name Email Confirm email Username But there is no password field. When they hit submit, they are ...
8
votes
6answers
694 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 ...
3
votes
2answers
2k views

Session Authentication vs Token Authentication

I am trying to get a handle on some terms and mechanisms and find out how they relate to each other or how they overlap. Authenticating a theoretical web application and mobile application is the ...
1
vote
1answer
134 views

User Authentication for a public website in 2015 [closed]

I am creating a new website for online shopping in .net and was wondering if i have another option beside Forms authentication to validate the users in a safe and secure way (this has been around for ...
1
vote
0answers
75 views

Questions about SRP algorithm

I trying to use SRP algorithm but I have some questions: Is that a good choice to use for registration and authorization SRP algorithm with SSL/TLS? And for all other transmission using just ...
0
votes
0answers
91 views

Brute-forcing a RSA private key password vs. LUKS volume

I need to store various private keys for my clients. Given these options, what would be the least prone to brute force attacks: Encrypt the private keys using a separate RSA key (each user get its ...
0
votes
3answers
114 views

Two factor authentication(Mobile)

Consider such two factor authentication on web site: say when user enters username/password on web site - and receives SMS on mobile phone number. For attacker to access this he must know your ...
0
votes
1answer
110 views

Mechanism used for offline authentication of software

To prevent user from downloading bootleg copies of software , users often have to enter a string of hexadecimal numbers which would be used to authenticate the user. I think the basic idea would be ...
1
vote
1answer
55 views

What is the term for requiring a user to go through an additional activation/verification process on new devices only?

When I log onto my bank's website on a new device (be it a new phone or a web browser I haven't used before) it prompts me to send an activation code to my phone or email. I have to enter in this ...
0
votes
3answers
144 views

What is a good way to authenticate a user to websites and applications with a smart phone?

What would be a good way to authenticate a user to authenticate to websites and applications over a smart phone? By good, I mean that it is both secure, and user-friendly. Passwords don't seem to be ...
27
votes
7answers
3k views

What is a good way to authenticate a user to a smart phone?

What would be a good way to authenticate a user to a smart phone? By good, I mean that it is both secure, and user-friendly. Passwords don't seem to be the best fit because a password needs to be ...
19
votes
5answers
3k views

How to uniquely identify users with the same external IP address?

I have created a login module on my website. I was able to deal with simple brute force attacks since I can identify the user based on username/email and throttle their login based on failed login ...
1
vote
2answers
128 views

Breaking mysql username and password form [closed]

I have two versions of a website. The first one has no security precautions against sql injections. So if I try something like: Username: hello_world Password: ' or ' 1=1 I'll be signed in as the ...
1
vote
1answer
91 views

Why is a cookie's life extended after half the time has passed on a sliding expiration algorithm?

I'm coding my sliding expiration algorithm for Bearer tokens to mimic what's done by Microsoft on their FormsAuthentication logic, and reading their documentation they say (emphasis added) When ...
0
votes
0answers
45 views

Implementation of AEAD_AES_256_GCM and AEAD_AES_128_GCM ciphers in secure RTP

I am in the process of implementing AEAD_AES_256_GCM and AEAD_AES_128_GCM ciphers in secure RTP. There is a mechanism in RFC 5116 to implement the algorithm, but I am not able to find any sample code ...
0
votes
1answer
71 views

Client authentication [closed]

Assume a server which offers some information which must not be exposed publicly. A client of this which may be e.g. a windows service (or at least something executing headless) needs to access the ...
1
vote
1answer
149 views

Encrypted access tokens - expiration date

My idea is to use encrypted tokens - where upon authentication (with username and password), backend would encrypt user_id, timestamp and an SHA-256 over those, base 64 encode it and return to the ...