5 ms·

My girlfriend worked at bank that did this. The alert PIN was your PIN backwards. I don't know if they still do this or not.

gillygize 15y ago
Out of curiosity, do you know what happened if the pin number was a palindrome? Did they restrict your selection to prevent that?
- Lost_BiomedE 15y ago
  Yes, they restricted the selection. They also encouraged each number to be unique.
  - botker 15y ago
    That's a funny requirement. Requiring uniques reduces password strength.
    - slowpoke 15y ago
      Bank PINs aren't really about password strength though. To prevent brute force, they simply block access after n tries (usually n = 3). They are just a way of preventing access to the card in case of loss or theft. So as long as there are enough combinations to make the chance of a successful brute force after three tries small enough, it doesn't really matter how strong the password is. For online banking, there are usually added security schemes and the PIN isn't used at all.
  - etcet 15y ago
    For the interested: enforcing no palindromes and unique digits reduces the number of possible PINs by about a factor of 2, bringing it down to 5040 4-digit combinations. [JS code] http://pastebin.com/3A46BP1C http://pastebin.com/3A46BP1C
    - Jabbles 15y ago
      If the digits are unique then there are no palindromes. Therefore there are 1098*7 = 5040 combinations.
      - etcet 15y ago
        The formatting ate your *'s but I understand. That's definitely the better way to reason the problem. In my defense it was late (after a trip to the bar) and my code is basically stream of consciousness.
deleted 15y ago
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samwillis 15y ago
I heard about this before. According to Snopes it's false although it may have been implemented in A few places. http://www.snopes.com/business/bank/pinalert.asp http://www.snopes.com/business/bank/pinalert.asp http://en.m.wikipedia.org/wiki/ATM_SafetyPIN_software http://en.m.wikipedia.org/wiki/ATM_SafetyPIN_software
- rplnt 15y ago
  Thanks for the wiki article. I've heard about it and was pretty sure it's a hoax (mostly because of the palindromes).
adolph 15y ago
Dang, no palindrome PINs then, eh?

gillygize 15y ago

Out of curiosity, do you know what happened if the pin number was a palindrome? Did they restrict your selection to prevent that?

Lost_BiomedE 15y ago
Yes, they restricted the selection. They also encouraged each number to be unique.
- botker 15y ago
  That's a funny requirement. Requiring uniques reduces password strength.
  - slowpoke 15y ago
    Bank PINs aren't really about password strength though. To prevent brute force, they simply block access after n tries (usually n = 3). They are just a way of preventing access to the card in case of loss or theft. So as long as there are enough combinations to make the chance of a successful brute force after three tries small enough, it doesn't really matter how strong the password is. For online banking, there are usually added security schemes and the PIN isn't used at all.
- etcet 15y ago
  For the interested: enforcing no palindromes and unique digits reduces the number of possible PINs by about a factor of 2, bringing it down to 5040 4-digit combinations. [JS code] http://pastebin.com/3A46BP1C http://pastebin.com/3A46BP1C
  - Jabbles 15y ago
    If the digits are unique then there are no palindromes. Therefore there are 1098*7 = 5040 combinations.
    - etcet 15y ago
      The formatting ate your *'s but I understand. That's definitely the better way to reason the problem. In my defense it was late (after a trip to the bar) and my code is basically stream of consciousness.

deleted 15y ago

[deleted]

samwillis 15y ago

I heard about this before. According to Snopes it's false although it may have been implemented in A few places. http://www.snopes.com/business/bank/pinalert.asp http://www.snopes.com/business/bank/pinalert.asp http://en.m.wikipedia.org/wiki/ATM_SafetyPIN_software http://en.m.wikipedia.org/wiki/ATM_SafetyPIN_software

rplnt 15y ago
Thanks for the wiki article. I've heard about it and was pretty sure it's a hoax (mostly because of the palindromes).

adolph 15y ago

Dang, no palindrome PINs then, eh?