diff --git a/spdl/soph-keyexch.spdl b/spdl/soph-keyexch.spdl
new file mode 100644
index 0000000..611ba09
--- /dev/null
+++ b/spdl/soph-keyexch.spdl
@@ -0,0 +1,39 @@
+usertype Sessionkey;
+const pk: Function;
+secret sk: Function;
+inversekeys (pk,sk);
+
+protocol sophkx(I,R)
+{
+	role I
+	{
+		const ni: Nonce;
+		const kir: Sessionkey;
+		var nr: Nonce;
+
+		send_1(I,R, ni, {I,kir}pk(R) );
+		read_2(R,I, {ni}kir );
+		claim_4(I,Secret,kir);
+	}	
+	
+	role R
+	{
+		var ni: Nonce;
+		var kir: Sessionkey;
+		const nr: Nonce;
+
+		read_1(I,R, ni, {I,kir}pk(R) );
+		send_2(R,I, {ni}kir );
+	}
+}
+
+const Alice,Bob,Eve: Agent;
+
+untrusted Eve;
+const nc: Nonce;
+const ke: Sessionkey;
+compromised sk(Eve);
+
+run sophkx.I(Agent,Agent);
+run sophkx.R(Agent,Agent);
+run sophkx.I(Agent,Agent);
diff --git a/spdl/soph.spdl b/spdl/soph.spdl
new file mode 100644
index 0000000..905dc61
--- /dev/null
+++ b/spdl/soph.spdl
@@ -0,0 +1,34 @@
+const pk: Function;
+secret sk: Function;
+inversekeys (pk,sk);
+
+protocol soph(I,R)
+{
+	role I
+	{
+		const ni: Nonce;
+
+		send_1(I,R, {I,ni}pk(R) );
+		read_2(R,I, ni );
+		claim_4(I,Niagree);
+	}	
+	
+	role R
+	{
+		var ni: Nonce;
+
+		read_1(I,R, {I,ni}pk(R) );
+		send_2(R,I, ni );
+	}
+}
+
+const Alice,Bob,Eve: Agent;
+
+untrusted Eve;
+const nc: Nonce;
+compromised sk(Eve);
+
+run soph.I(Agent,Agent);
+run soph.R(Agent,Agent);
+run soph.I(Agent,Agent);
+run soph.R(Agent,Agent);