A method is provided for secured transfer of data from a first memory
containing the data element to a second memory through a data bus that is
connected between the first memory and the second memory. According to
the method, a secret N-byte data element is transferred byte-by-byte
through the data bus, with each byte transiting at least once on the data
bus. Before each transfer of a byte of the secret data element, a current
index ranging from 0 to N-1 is randomly chosen, with the current index
corresponding to a place value of the byte to be transferred. At each
transfer of a byte of the secret data element with a place value equal to
the current index, a corresponding bit of an N-byte loading indicator is
modified as a function of a loading mode, with the loading mode being an
integer ranging from 0 to a first constant. The transfer of the secret
data element is ended when the loading indicator takes a predetermined
value.