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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48 views

Restrict access to admin area by checking SSH connections

Assuming that the users have dynamic IPs (so I can't whitelist) and that setting up a VPN is not an option, is it a valid approach to restrict access to an administration area by only allowing IPs ...
1
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3answers
58 views

Is it ok to use the same password for many services with two-factor authentication?

Let's say that I've a relatively strong password, but I don't want to use many different passwords for each different service, and let's say that those services provide two-factor authentication using ...
13
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2answers
627 views

Is it okay to sign a PGP key without an IRL meeting?

[PGP] can get paralyzed by excessive analness. — Phil Zimmermann Preamble I am in the process of building my own web of trust. That is, I want people (PGP users…) to be—fairly—sure that, by ...
6
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3answers
2k 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 ...
4
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2answers
112 views

What's the meaning of the term “ad-hoc MAC” (Message Authentication Code)?

In SSL literature, I've noticed the use of the term "ad-hoc MAC". I understand the meaning of MAC (Message Authentication Code) and how it works, but what does the term Ad-hoc MAC mean? Note: With ...
54
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7answers
33k views

Certificate based authentication vs Username and Password authentication

What are the advantages and drawbacks of the certificate based authentication over username and password authentication? I know some, but I would appreciate a structured and detailed answer. UPDATE ...
2
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1answer
115 views

SAML and OpenID, centralized and decentralized

I'm learning SAML, which is said to be centralized. To understand the difference with decentralized, I'm reading about OpenID. I find it difficult to understand the difference between the two, ...
2
votes
5answers
324 views

What is the most credible timestamp I can create for a digital file?

Is it possible to create a timestamp that is so hard to fake, that it could be used as proof or simply strong evidence in a court of law, that something was not created after a certain point in time? ...
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2answers
144 views

How to avoid DDOS against Kerberos Authentication Server

I have a school project where i am supposed to implement a Kerberos based infrastructure (AS, TGS and resource server). It is already done and working, but i started thinking about how to protect the ...
5
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4answers
7k views

Secure use of psexec or better alternative to it

I want to remotely start VMWare virtual machines (I own VMWare Workstation) and to this end I need to execute on host something like "vmrun -T ws H:\VMWare\VM1\VM1.vmx nogui" with user desktop ...
2
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4answers
276 views

how secure is rsa encryption for a web login without https?

I have a server running rstudio. This is basically a web application, and it is currently only accessible over the local network. The web app takes your Linux username/password in order to log you ...
0
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2answers
60 views

Is it safe to use a ECDSA public key as a password seed for GCM/AES?

Two peers already exchanged their ECDSA (curve secp256k1) public keys using a secure channel. They want to establish an authenticated encrypted channel between them. They will use CCM mode and with ...
2
votes
1answer
185 views

How do application specific passwords work in Google accounts? [duplicate]

I turned on 2-step verification and had to setup an application specific password for Outlook. I noticed the password generated is actually weaker than the one I had before turning on 2-step ...
17
votes
9answers
3k views

Can IP address be a component of 2-factor authentication?

I have a bunch of Linux machines that I wish to administer over the Internet. I currently use SSH keys, but have been advised to use 2-factor authentication. SSH Keys are something you know. Is an IP ...
1
vote
1answer
105 views

Securing Javascript plugin

My company offers a Javascript plugin that is meant to be embedded with websites. It works in a similar fashion to Google Analytics, in which you add a bit of Javascript and then it does some magic on ...
0
votes
2answers
62 views

Can session data be manipulated without access to source code

When implementing a web-based application, how secure are any session variables against manual manipulation beyond the scope of my code? i.e. when a user is authenticated, if I were to initialise a ...
1
vote
1answer
111 views

SSL Handshake random number?

I realized all of the phase of the handshake but I do not understand how it does that from the two randomly generated numbers are unable to generate a session key that the client and the server uses ...
1
vote
1answer
84 views

Amazon Turk - How secure is it? Strange behavior

I just had this really strange experience with Amazon Turk, where suddenly I was logged into someone else's account. I was logged into the company's Turk account, left my computer for a while, ...
0
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0answers
31 views

Can the device seed be recovered from the iPhone/Android RSA SecurID app?

The Windows RSA SecurID app allows the device seed to be determined and cloned from one machine to another (see this blog post). Do either the iPhone or Android RSA SecurID apps suffer from the same ...
3
votes
2answers
102 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 ...
0
votes
1answer
245 views

Use SSH config file with Putty [closed]

I'm using SourceTree (a Git GUI) which uses PuTTY as SSH client. I need to push some code into a repository for which I need to tunnel through SSH to do so. The trouble is, the repository and SSH ...
3
votes
1answer
691 views

Why is OAuth 2.0 being used for mobile devices, and not OpenID?

Microsoft Azure Mobile services exclusively uses OAuth 2.0 for authentication, and many other providers mention the use of OAuth 2.0 specifically when referring to mobile devices. Question What ...
8
votes
2answers
422 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 ...
3
votes
2answers
900 views

How can I implement authentication in my proxy server?

I have a proxy server, it will have a captive portal page. Users will be required to sign in before gaining access to the internet. So far I am aware of IP and/or MAC address based authentication. ...
6
votes
5answers
1k views

Preventing online voter fraud

As part of a promotional campaign, my company wants to launch a site where users (and potential users) of our product will be required to register and vote for certain choices. Depending on how ...
3
votes
3answers
405 views

Should email verification links be 'time limited' after user registration?

Regarding web application user management, I understand that password reset links are effectively "password equivalents", and therefore it makes sense to limit them to one use only and also make them ...
3
votes
3answers
2k views

What is the exact difference between SAMLp and WS-Trust?

They seem to be similar on the surface, but I'm not sure how deep the differences are. Can someone explain to me the difference between SAMLp and WS-Trust? ADFSv2 gives me a choice between these ...
1
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3answers
122 views

How can I add a layer of security to cleartext passwords and SSL?

I'm creating a web API in .Net for a web application. I'm wondering what the industry standard for login authentication is. I know that most people believe that sending cleartext username/passwords ...
0
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1answer
609 views

What happens if you run out of password attempts?

In Samsung Knox, you have 20 password attempts. However, it is never explained what happens if you run out of attempts. Does it delete your Knox data, do you need to enter the recovery PIN or is it ...
8
votes
3answers
487 views

Why would a website allow answers to security questions to be used interchangeably?

I needed to reset my password on a website that uses security questions for the purpose, and I noticed something strange. My hypothetical security questions are (not the ones I actually use) are: ...
1
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1answer
87 views

Web Application Authentication Using Computer Properties

Introduction: I am in the process of building a web-based game that requires user authentication. The vast majority of other gaming sites utilize the typical username/password method for ...
0
votes
1answer
43 views

Evaluation of cryptosystem for authentication and keyexchange

I'm a masters student in computer science who works part time with my own company as a consultant. My lastest project is based on my bachelor thesis which handles everything except the security. The ...
1
vote
2answers
126 views

How to make an efficient bruteforce attack on Windows? [closed]

I've been trying to figure out a way to efficiently bruteforce on Windows, but the method I currently have isn't very efficient. I did some profiling and found out that on average it can go through ...
-4
votes
3answers
2k views

How do I hack this login page by using SQL injection? [closed]

I'm testing a client's web site vulnerability to SQL injection, which appears to be the case. The web site is hosted in IIS on a Windows server and is using Microsoft's .NET framework with SQL. I'm ...
1
vote
0answers
75 views

Login Authentication with SSL and HMAC

My question is pretty similar to : http://stackoverflow.com/questions/5487757/using-hmac-sha1-for-api-authentication-how-to-store-the-client-password-secure. Basically, I want to write an API for my ...
0
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0answers
82 views

Client-server authentication protocol suggestion

I'm designing an authentication methods for my client/server system consisting of: a windows desktop client application (.NET) windows/linux servers (C++) one "security server" which authorizes the ...
1
vote
1answer
119 views

Confused about the most relevant way to secure my APIs

I own a Javascript application (Single Page Application) hitting some apis from my own RESTful backend. What I expect for my authentication/(authorization) mechanism is three things: Preventing ...
16
votes
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 ...
1
vote
1answer
57 views

Any known protocol for establishing trust between an inherently untrustworthy source and a server without a 3rd party?

Is there any kind of protocol, scheme, or theoretical paper out there that implements or examines the problem of establishing trust between two parties (communicating, listening) where the ...
6
votes
3answers
1k views

What's wrong with my own authentication scheme?

So I want to write my own authentication scheme for a web-app server, as follows. I assume this is a Bad Idea from either security or cost-effectiveness reasons and I know the conventional wisdom is ...
3
votes
2answers
798 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 ...
4
votes
3answers
173 views

Why do some websites need time to log you in securely, while others can do it instantly?

I noted that on a lot of money-related websites (banks, paypal, etc), you are brought to a page that "logs you in securely". This is an example of one: Meanwhile, websites that also store very ...
1
vote
1answer
39 views

Issues of using HOTP w/ iteration window

I am using HOTP to generate OTP to validate a request, in order to prevent replay attacks. I'm thinking about using a window of 10 (or so) iterations to accommodate a possible mismatch in the counter ...
1
vote
3answers
48 views

Secure Custom Registration Links

I'm working on a website that allows a current user to invite another individual to be friends by typing in the non-user's email address. The non-user would then receive a custom registration url by ...
1
vote
0answers
42 views

Considerations when implementing a key based SSH-like auth scheme

I have a SMTP server where all the users (for an unrelated reason) will have public keys tied to their username and registered with the server. I want to add a non-standard extension that uses these ...
1
vote
1answer
80 views

Client authentication flaw in old Netscape SSL protocol

Below is a screenshot from the paper "Prudent Engineering Practice for Cryptographic Protocols" by Martin Abadi and Roger Needham. I can't see what's wrong with the protocol and what the fix achieves. ...
20
votes
4answers
6k views

How secure is Windows 8's Picture Password login?

The final Windows 8 build has been released to manufacturing. One of the new features of Windows 8 is "Picture Password", where the end user logs on to Windows by clicking a specific pattern on the ...
4
votes
2answers
461 views

Is OATH TOTP and / or Google Authenticator vulnerable if an attacker has (N) previous codes?

I'm not much of a ipsec initiate, so this is a bit over my head ... but I'm always willing to learn more. Are there any known attacks against OATH TOTP (Google Authenticator's / Authy's algorithm) if ...
1
vote
0answers
92 views

Can we create custom APDU for non-smart (memory type) contactless card?

I want to implement card-based authentication for the parking system in a university. Currently all students own a Java Card-based student ID card, if they have not broken or lost it. Can we create ...
3
votes
1answer
94 views

Is there an actual use for OpenPGP authentication keys?

The OpenPGP specification (RFC 4880) describes, page 34, the different capabilities that an OpenPGP key may have; including: 0x20 - This key may be used for authentication. In GnuPG, one of the ...