Barclays Pin Sentry in The AnswerBank: Personal Finance

frankief

You're not a criminal are you?

Davexevad

Question Author

Damn, you sussed me out. You going to give me an answer now? (I'll cut you in!).

bigmamma

Hello , I 've had one for months and , if I can use it then it's easy . Your card slots into the small pin sentry machine at your home when using on-line banking .It gives you a different number code each time , which you enter to access your on-line banking.
xxx

Davexevad

Question Author

Think you may have missed my point, bigmamma. I use it easily enough but am unsure as to why it works as there is no link between the sentry and my pc/internet, so how does it recognise the code I put in from the sentry?
Cheers

dzug

Don't know the details, but Barclays central computer must generate the same number as the Pin Sentry.

buildersmate

Generically the way these devices work is from the ID code on the back, which would have set up to be associated with your account at the outset. So although it produces what appears to be a random number, it is actually pseudo-random in that the secutity recognition device at Barclays as you sign in recognises that the code you entered is of a type that must have been produced by the local device that you have been given. Clearly few people know what algorithm links the two together, but the main point is that just knowing one security number presented by the device on one occasion (by skimming your details) doesn't help - I guess because the central device remembers what code was (validly) used by you last time around - and it will only work with a differently generated code on the subsequent occasion. There must be hundreds of combinations before the local device repeats itself.

Davexevad

Question Author

Thanks my builder friend....but you still haven't done enough to convince me....or maybe I'm just being dim. Maybe I should ask Barclays!

buildersmate

That's the way I think the device I have works (not Barclays - another bank). Maybe the Sentry system is different.

bigmamma

Lol , sorry Davexevad . Buildersmate the pin sentry can be used on other comps and can be used by more than one person .

frankief

Yes, ask Barclays - i'm sure they will send you a manual!
Sorry to be suspicious in my earlier reply - it's just that we are getting a lot of posters on here with questions like 'where can I download sort codes for banks' etc !! You're not Nigerian are you?

Dikastes

It is a time-synchronous keypad machine. The pinsentry takes the shared secret (pin) and the time and encrypts it providing a magic number (8 digit number). The Barclays bank computer, using a very clever piece of software, algorithm, de-crypts the magic number and bingo, you have access to your bank account.(There is a specific time frame for the magic number to be entered into you internet banking system. If the time is exceeded you cannot gain entry and so need another magic number from the pin sentry). Simple really!!!

Dikastes

It is a time-synchronous keypad machine. The pinsentry takes the shared secret (pin) and the time and encrypts it providing a magic number (8 digit number). The Barclays bank computer, using a very clever piece of software, algorithm, de-crypts the magic number and bingo, you have access to your bank account.(There is a specific time frame for the magic number to be entered into you internet banking system. If the time is exceeded you cannot gain entry and so need another magic number from the pin sentry). Simple really!!!

anon_private

Surely, if Pinsentry just takes a PIN and the date and/time, when the Barclays computer decrypts the number it would just get the PIN and the date/time

Barclays Pin Sentry

Answers