Method for making secure transactions

Abstract

The invention concerns a method for carrying out a transaction comprising prior steps of identifying the card by reading its number and authenticating the bearer optionally by writing in the secret code using a keyboard. The invention is characterised in that the secret code and/or the card number, comprise(s) in a specific position at least a character modified at each transaction. The modified character(s) (n) of the secret code and/or the card is/are modified in accordance with at least a character of a predetermined parameter.

1 - 12 . (canceled) 
     
     
         13 . A method for performing secure transactions involving an account provided with an owner identification number, said transactions including the steps of identifying said account via a telecommunications transaction for communication of said identification number, said transactions being the type in which the identification number of said account comprises, in positions predetermined by arrangement with the institution handling the transactions, at least one character that is modifiable with each of a sequence of transactions, and modifying said character as a function of at least one character of at least one predetermined parameter, and being characterized in that said predetermined parameter is an element of at least one event that is random in nature, chosen by agreement with said institution for securing said transaction. 
     
     
         14 . A method as defined in  claim 13  including a further step of selecting a previous transaction as said event that is random in nature for facilitating memorization of said owner. 
     
     
         15 . A method as defined in  claim 13  including a further step of selecting an identifier of a merchant involved in said transaction as said event that is random in nature for further securing said transaction. 
     
     
         16 . A method according to  claim 13  characterized in that said function acts on a parameter that depends on the location, the merchant, or the terminal at which said transaction is performed. 
     
     
         17 . A method according to  claim 13  characterized in that said function acts on at least two parameters, each depending on a different event. 
     
     
         18 . A method for performing secure transactions involving an account provided with an identification number and a secret code, said transactions including the steps of identifying said account via a telecommunications transaction for communication of said identification number and said secret code, said transactions being the type in which the identification number of said account comprises, in positions predetermined by arrangement with the institution handling the transactions, at least one character that is modifiable with each of said transactions, and modifying said character as a function of at least one character of at least one predetermined parameter, and being characterized in that said predetermined parameter is an element of at least one event that is random in nature, chosen by agreement with said institution for securing said transaction. 
     
     
         19 . A method according to  claim 18  including the step of using a second secret code for telecommunication transactions the characters of which are changeable with each transaction as a function of one or more of said predetermined parameters. 
     
     
         20 . A method for performing secure transactions involving an account provided with an owner identification number, said transactions including the steps of identifying said account via a telecommunications transaction for communication of said identification number, wherein the institution handling said transactions introduces new characters differing from the characters of said identification number for facilitating a secure transaction, 
     
     
         21 . A method according to  claim 20  wherein said new characters are random in nature. 
     
     
         22 . A method according to  claim 20  wherein said new characters are correlated with the date of said transaction. 
     
     
         23 . A method according to  claim 20  wherein said new characters are correlated with the amount of said transaction. 
     
     
         24 . A method according to  claim 20  wherein said new characters are correlated with the date and the amount of said transaction. 
     
     
         25 . A method according to  claim 21  wherein said new characters are correlated with the date of said transaction. 
     
     
         26 . A method according to  claim 21  wherein said new characters are correlated with the amount of said transaction. 
     
     
         27 . A method according to  claim 21  wherein said new characters are correlated with the date and the amount of said transaction.