Update doc/std/hashers.md for timing attacks
@@ -15,6 +15,9 @@ twice with two different slices should be equivalent to calling it once on
their concatenation. [Re-initialize](/doc/note/initialization.md) the object to
reset the state.
+Wuffs' hasher implementations are not cryptographic. They make no attempt to
+resist timing attacks.
+
## Implementations
