diff --git a/PROTOCOL.md b/PROTOCOL.md
index c87f644..4733ac4 100644
--- a/PROTOCOL.md
+++ b/PROTOCOL.md
@@ -117,9 +117,9 @@ When the client switches to a new key, it has to store the new keyset along the
 | Step | Calculation |
 |:--------:|:------|
 | `1` | Decrement $n$ |
-| `2` | $t\_c = \mid \frac{t\_{now}}{W}\mid$ |
+| `2` | $t\_c = \mid \frac{t\_{now}}{W}\mid, m\_c = t\_c \ \mathbb{Z}\_{(2)}$ |
 | `3` | $x\_1 = h^{n}(K) \oplus h(t\_c)$ |
-| `4` | $x\_2 = x\_1 \oplus (t\_c \ \mathbb{Z}\_{(2)})$ |
+| `4` | $x\_2 = x\_1 \oplus m\_c$ |
 | `5` | if $i <= min+belt \Rightarrow s = 1$ |
 
 Send $x_1$ and $x_2$.
@@ -128,7 +128,7 @@ Send $x_1$ and $x_2$.
 
 | Step | Calculation |
 |:--------:|:------|
-| `1` | $t\_c = \mid \frac{t\_{now}}{W}\mid$ |
+| `1` | $t\_c = \mid \frac{t\_{now}}{W}\mid, m\_c = t\_c \ \mathbb{Z}\_{(2)}$ |
 | `2` | $x\_1 = h^{n}(K) \oplus h(t\_c)$ |
 | `3` | Generate $(K',n',s')$ until <br><ul><li>$[(h^n(K) \oplus h^{n'}(K')) \And 0x1] \ \mathbb{Z}\_{(2)} = m\_c$</li><li>$[(h^N(K) \oplus h^{n'}(K')) \And 0xf0] \ \mathbb{Z}\_{(3)} = s$</li></ul> |
 | `4` | $x\_2 = h^{n'}(K') \oplus h(t\_c)$ |