How to generate OTP Number with 6 digits

java android one-time-password
Android Developer picture Android Developer · Jun 20, 2015 · Viewed 70.1k times · Source

What is an OTP number in a login authentication system? Is there any specific algorithm for generating OTP numbers using java (android). Or is an OTP something like random number? How can this be achieved, with optimization.

Answer

cornelinux picture cornelinux · Sep 9, 2015

Please do not reinvent the wheel - especially in case of security and cryptography. You might end up in a really bad state.

Use algorithms, that the community agreed upon like the HOTP and TOTP algorithm specified by the Open Authentication Iniative. These algorithms are also used by the google authenticater and specified in these RFCs. Read them. They are simple.

http://tools.ietf.org/html/rfc4226

https://tools.ietf.org/html/rfc6238

Related questions

Can't start Eclipse - Java was started but returned exit code=13

I am trying to get my first taste of Android development using Eclipse. I ran into this problem when trying to run Eclipse, having installed version 4.2 only minutes ago. After first trying to start Eclipse without any parameters to specify …

Read More
How to fix 'android.os.NetworkOnMainThreadException'?

I got an error while running my Android project for RssReader. Code: URL url = new URL(urlToRssFeed); SAXParserFactory factory = SAXParserFactory.newInstance(); SAXParser parser = factory.newSAXParser(); XMLReader xmlreader = parser.getXMLReader(); RssHandler theRSSHandler = new RssHandler(); xmlreader.setContentHandler(theRSSHandler); InputSource is = new InputSource(…

Read More
Converting double to string

I am not sure it is me or what but I am having a problem converting a double to string. here is my code: double total = 44; String total2 = Double.toString(total); Am i doing something wrong or am i missing …

Read More