Does server stores my previos passwords?












1














When I change my password on some web server like email, cloud, social network and try to use my previous password, server denied it with message "Don't use your previous passwords".
- Does it mean that server stores my my previous passwords? How does it secure?






passwords







share|improve this question



























    1














    When I change my password on some web server like email, cloud, social network and try to use my previous password, server denied it with message "Don't use your previous passwords".
    - Does it mean that server stores my my previous passwords? How does it secure?






    passwords







    share|improve this question

























      1












      1








      1







      When I change my password on some web server like email, cloud, social network and try to use my previous password, server denied it with message "Don't use your previous passwords".
      - Does it mean that server stores my my previous passwords? How does it secure?






      passwords







      share|improve this question













      When I change my password on some web server like email, cloud, social network and try to use my previous password, server denied it with message "Don't use your previous passwords".
      - Does it mean that server stores my my previous passwords? How does it secure?






      passwords




      passwords






      share|improve this question













      share|improve this question











      share|improve this question




      share|improve this question










      asked 2 hours ago









      sluge

      401144




      401144






















          1 Answer
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          Hash functions deterministic functions, same input results always the same output. They can store the previous hash values of your old passwords and compare them with your new proposed password's hash. To achieve this, they also need to store at least the salt values, too. This means the salt and other parameters has to be the same for you in this site.



          From here, without the server side code, we cannot say more than like this.






          share|improve this answer



















          • 1




            Especially if salt is a user name or user's email.
            – sluge
            2 hours ago











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          1






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          oldest

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          active

          oldest

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          Hash functions deterministic functions, same input results always the same output. They can store the previous hash values of your old passwords and compare them with your new proposed password's hash. To achieve this, they also need to store at least the salt values, too. This means the salt and other parameters has to be the same for you in this site.



          From here, without the server side code, we cannot say more than like this.






          share|improve this answer



















          • 1




            Especially if salt is a user name or user's email.
            – sluge
            2 hours ago
















          2














          Hash functions deterministic functions, same input results always the same output. They can store the previous hash values of your old passwords and compare them with your new proposed password's hash. To achieve this, they also need to store at least the salt values, too. This means the salt and other parameters has to be the same for you in this site.



          From here, without the server side code, we cannot say more than like this.






          share|improve this answer



















          • 1




            Especially if salt is a user name or user's email.
            – sluge
            2 hours ago














          2












          2








          2






          Hash functions deterministic functions, same input results always the same output. They can store the previous hash values of your old passwords and compare them with your new proposed password's hash. To achieve this, they also need to store at least the salt values, too. This means the salt and other parameters has to be the same for you in this site.



          From here, without the server side code, we cannot say more than like this.






          share|improve this answer














          Hash functions deterministic functions, same input results always the same output. They can store the previous hash values of your old passwords and compare them with your new proposed password's hash. To achieve this, they also need to store at least the salt values, too. This means the salt and other parameters has to be the same for you in this site.



          From here, without the server side code, we cannot say more than like this.







          share|improve this answer














          share|improve this answer



          share|improve this answer








          edited 2 hours ago

























          answered 2 hours ago









          kelalaka

          6251615




          6251615








          • 1




            Especially if salt is a user name or user's email.
            – sluge
            2 hours ago














          • 1




            Especially if salt is a user name or user's email.
            – sluge
            2 hours ago








          1




          1




          Especially if salt is a user name or user's email.
          – sluge
          2 hours ago




          Especially if salt is a user name or user's email.
          – sluge
          2 hours ago


















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