2
votes
0answers
31 views

Google Authenticator Error on Reboot

I have set up an SSH server to accept only login using codes generated by Google Authenticator (I have disabled all other forms of authentication on that port). After having rebooted my remote ...
0
votes
0answers
26 views

Algorithm to Transaction Data Signing

Transaction Data Signing I need an idea to develop a very secure algorithm to authenticate online operations using PHP in the server and an Android app in the user's device. What is the idea? The ...
0
votes
1answer
77 views

Storage of the One Time Password Seed

I'm a student and I'm working on an OTP authentication systeme based on OATH using smart phones as tokens for the clients. My problem is the protection the OTP seed at both client and validation ...
1
vote
1answer
36 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
2answers
405 views

How to write a rock solid TOTP implementation?

I am currently writing a TOTP implementation in PHP (but this applies to other languages as well) and of course want it to be as secure as possible, what should be considered? After reading the ...
3
votes
1answer
113 views

Should an administrator be able to turn off TFA for a user

We use Google Authenticator and SMS for two factor authentication. Should we allow the administrators of the site to turn off TFA for users? Google Auth uses SMS as backup option but SMS does not ...
0
votes
2answers
726 views

Google Authenticator - Counter Based [duplicate]

I'm trying to understand How google authenticator - counter based work. I have tried googling around finding a demo or at least how this work. I understand its a one time password but not like TOTP. I ...
0
votes
1answer
144 views

Storing Seed for TOTP

We have a public website for employees which has access to some sensitive company information. To make the login process more secure we want to implement TOTP. The setup and implementation has been ...
4
votes
2answers
447 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 ...
0
votes
2answers
160 views

Using authentication only one time passwords [duplicate]

I would be interested in advice. Imagine a authentication mechanism where users are authenticated ONLY using some code (e.g., one time password) which they receive (say as SMS) on their mobile phone? ...
10
votes
4answers
625 views

What is the use of the “secret” displayed when setting up 2 Factor Authentication?

What is the purpose of the "secret" that is displayed when you take the picture of the QR code to set up 2 Factor Authentication on a non-Google site? Why would you need it? If you save it, doesn't ...
58
votes
3answers
13k views

How does Google Authenticator work?

Google Authenticator is an alternative to SMS for 2Step verification, installing an app on Android where the codes will be sent. It works without any connectivity; it even works on plane mode. This ...
1
vote
1answer
141 views

What manufacturers create OATH HOTP cards now that InCard Technologies is no longer in business?

I purchased the following OAUTH HOTP card from Verisign. I'm intrigued by the security possibilities that this form factor provides and what customizations to the circuit logic are possible. On ...
2
votes
2answers
122 views

Client code tampering detection

I have a server in a trusted environment. This server handles requests from clients in an a non-trusted environment. I'd like to authenticate each request and to know if the client code has been ...
1
vote
1answer
296 views

What is more secure for voice and SMS OTP: A random number or generated similar to HOTP?

Many providers are creating OTP authentication for their sign in. However I noticed that all the voice and SMS OTPs I've come across are a series of 6 digits... similar to the HOTP RFC Standard ...
10
votes
3answers
896 views

What is the risk and mitigation of accidentally typing a YubiKey password in an open forum?

I have a YubiKey in my laptop (for testing) and accidentally broadcast my YubiKey password out to the Internet. Since this is only a test key, and has no access to anything of value, here are some ...
1
vote
2answers
327 views

Can I use hardware token OTP to stop piracy?

Our firm sells an offline desktop (.exe) software, we are thinking of using OTP (from hardware token like in internet banking) to stop people from copying the software without permission. Basically, ...
7
votes
2answers
570 views

Replacement for One Time Passwords (OTP)

OTP may known as new generation of password security techniques, but I want to know does it still safe enough after several years of appearance or it will deprecate soon? & what would be the ...
2
votes
3answers
248 views

Why would it be a good idea for someone to get or not to get a Yubi key [closed]

In what uses would it be smart to get a Yubi key?
1
vote
1answer
98 views

How to detect suspicious tokens collected by a hacker

I previously asked a question here What's the use of adding a challenge in the otp algorithm? Let's suppose that a hacker has succeeded to collect tokens. Is there a way to detect suspicious ...
3
votes
1answer
2k views

Please explain Time-step in Time-Based One-Time Password Algorithm

I am studying about OTPs (One Time Passwords). I have gone through all the methods: HOTP (HMAC-based One Time Password), TOTP (Time-based One Time Password) I have no issues with HOTP. But according ...
3
votes
3answers
1k views

Mobile OTP - Secure?

I came across Mobile-OTP, "a de facto standard for strong mobile authentication" (http://motp.sourceforge.net). The developers claim that it is very secure etc. Reading through the implementation, I ...