diff options
Diffstat (limited to 'pyecsca/ec/scalar.py')
| -rw-r--r-- | pyecsca/ec/scalar.py | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/pyecsca/ec/scalar.py b/pyecsca/ec/scalar.py index dc6101c..eba80cf 100644 --- a/pyecsca/ec/scalar.py +++ b/pyecsca/ec/scalar.py @@ -128,6 +128,13 @@ def naf(k: int) -> List[int]: """ Compute the NAF (Non-Adjacent Form) of the scalar `k`. + Properties ([GECC]_ 3.29): + a) k has a unique NAF denoted NAF(k). + b) NAF(k) has the fewest non-zero digits of any signed digit representation of k. + c) The length of NAF(k) is at most one more than the bit-length of k. + d) If the length of NAF(k) is l, then $2^l / 3 < k < 2^(l+1) / 3$. + e) The average density of non-zero digits among all NAFs of length l is approximately 1/3. + :param k: The scalar. :return: The NAF. """ |