Method for access to all the cells of a memory area for purposes of writing or reading data blocks in said cells

An access method to access to cells in a memory area of a card for purposes of writing or reading data blocks in said cells, wherein said method comprises:

• for each access time to said cells in said memory area to be accessed, performing an process of address determining an address of a cell of the memory area to be accessed at said access time, the address determined for an access time not being once again determined for another access time;
• and
• determining the value of a random number;
• wherein said address determination process comprises:
• randomly determining a random bit which can thus take either a first value or a second value;
• and
• calculating a mask value and applying to said value of the random number a bitwise logic AND operation with said mask, and
• applying to an index determined for the access time in question a bitwise exclusive OR logic operation with a result of said logic AND operation, the value resulting from the exclusive OR operation being the value of the address for access to the cell of the memory area to be accessed at said access time.

An access method to access to cells in a memory area of a card for purposes of writing or reading data blocks in said cells, wherein said method comprises:

• for each access time to said cells in said memory area to be accessed, performing a process of address determining an address of a cell of the memory area to be accessed at said access time, the address determined for an access time not being once again determined for another access time, the address determination process comprising:
• randomly determining a random bit which can thus take either a first value or a second value;
• testing the value taken by said random bit that switches said process either to:
• (1) determining a value index as being equal to the value of a first index, followed by incrementing a unit of said first index, or
• (2) determining said value index as being equal to the value of a second index, followed by decrementing a unit of said second index,
• the value of said value index being the value of said address of the cell of the memory area to be accessed at said access time;
• and
• applying to the value index a bitwise exclusive OR operation with a random number before the address determination process.