1 files changed, 20 insertions, 0 deletions
diff --git a/pyecsca/ec/mod.py b/pyecsca/ec/mod.py
index a142b71..2b16a07 100644
--- a/pyecsca/ec/mod.py
+++ b/pyecsca/ec/mod.py
@@ -1,7 +1,10 @@
+import secrets
 from functools import wraps
 
 from public import public
 
+from .context import Action
+
 
 @public
 def gcd(a, b):
@@ -48,6 +51,18 @@ def check(func):
 
     return method
 
+@public
+class RandomModAction(Action):
+    """A random sampling from Z_n."""
+    order: int
+
+    def __init__(self, order: int):
+        super().__init__()
+        self.order = order
+
+    def __repr__(self):
+        return f"{self.__class__.__name__}({self.order:x})"
+
 
 @public
 class Mod(object):
@@ -120,6 +135,11 @@ class Mod(object):
         q, r = divmod(self.x, divisor.x)
         return Mod(q, self.n), Mod(r, self.n)
 
+    @staticmethod
+    def random(n: int):
+        with RandomModAction(n):
+            return Mod(secrets.randbelow(n), n)
+
     def __int__(self):
         return self.x