Patent ID: 7020640

Claim:
A method for certifying data containing a sequence of transactions comprising the following steps: finding a new transaction added to the sequence; electronically computing a certification code for the new transaction taking into consideration all data preceding the transaction in the preserved order using a certification code computed for a previous transaction in combination with the transaction data; saving the computed certification codes; finding a last certified transaction corresponding to the highest sequence number; if the last certified transaction is found; retrieving the sequence number of the last certified transaction; setting a counter with the retrieved sequence number of the last certified transaction; incrementing the sequence number; retrieving the certification code of the last certified transaction; setting a new certification code with the retrieved code certification code of the last certified transaction; if the last certified transaction is not found: initializing the sequence number with an initial number; initializing the last certification code with an initial code; checking if there is a transaction without a counter number; stopping the method if a transaction without a counter number is not found; saving the sequence number within a record; computing the certification code using the last certification code and the transaction data; saving the certification number with the transaction data; incrementing the sequence number; repeating from the step of checking if there is a transaction without a counter number.