diff --git a/metropolis/node/core/cluster/cluster_bootstrap.go b/metropolis/node/core/cluster/cluster_bootstrap.go
index 312874d..774359e 100644
--- a/metropolis/node/core/cluster/cluster_bootstrap.go
+++ b/metropolis/node/core/cluster/cluster_bootstrap.go
@@ -27,6 +27,7 @@
 	"google.golang.org/protobuf/proto"
 
 	"source.monogon.dev/metropolis/node/core/curator"
+	"source.monogon.dev/metropolis/node/core/identity"
 	"source.monogon.dev/metropolis/pkg/supervisor"
 
 	apb "source.monogon.dev/metropolis/proto/api"
@@ -101,7 +102,7 @@
 	directory := &cpb.ClusterDirectory{
 		Nodes: []*cpb.ClusterDirectory_Node{
 			{
-				PublicKey: pub,
+				Id: identity.NodeID(pub),
 				Addresses: []*cpb.ClusterDirectory_Node_Address{
 					{
 						Host: "127.0.0.1",
diff --git a/metropolis/node/core/cluster/cluster_register.go b/metropolis/node/core/cluster/cluster_register.go
index 90d48f4..bac85db 100644
--- a/metropolis/node/core/cluster/cluster_register.go
+++ b/metropolis/node/core/cluster/cluster_register.go
@@ -56,17 +56,6 @@
 				return fmt.Errorf("NodeParameters.ClusterDirectory.Nodes[%d].Addresses[%d] (%q) invalid: not a parseable address", i, j, add.Host)
 			}
 		}
-		if len(node.PublicKey) != ed25519.PublicKeySize {
-			return fmt.Errorf("NodeParameters.ClusterDirectory.Nodes[%d] invalid: PublicKey invalid length or not set", i)
-		}
-	}
-
-	// Strip the initial ClusterDirectory of any node public keys that might have
-	// been included, as it can't be relied on beyond providing cluster endpoint
-	// addresses, considering its untrusted origin (ESP). This explicitly enforces
-	// suggested usage described in ClusterDirectory's protofile.
-	for i := range register.ClusterDirectory.Nodes {
-		register.ClusterDirectory.Nodes[i].PublicKey = nil
 	}
 
 	// Validation passed, let's start working on registering us into the cluster.
diff --git a/metropolis/node/core/curator/impl_leader_management.go b/metropolis/node/core/curator/impl_leader_management.go
index 0f0bfe1..9d5b4cd 100644
--- a/metropolis/node/core/curator/impl_leader_management.go
+++ b/metropolis/node/core/curator/impl_leader_management.go
@@ -111,7 +111,7 @@
 			})
 		}
 		directory.Nodes[i] = &cpb.ClusterDirectory_Node{
-			PublicKey: node.pubkey,
+			Id:        node.ID(),
 			Addresses: addresses,
 		}
 	}
diff --git a/metropolis/proto/common/common.proto b/metropolis/proto/common/common.proto
index fc461ab..653b0d2 100644
--- a/metropolis/proto/common/common.proto
+++ b/metropolis/proto/common/common.proto
@@ -172,7 +172,8 @@
 // directory.
 message ClusterDirectory {
     message Node {
-        bytes public_key = 1;
+        string id = 3;
+        reserved 1;
         message Address {
             string host = 1;
         };
diff --git a/metropolis/test/e2e/BUILD.bazel b/metropolis/test/e2e/BUILD.bazel
index 3923c8d..812bc93 100644
--- a/metropolis/test/e2e/BUILD.bazel
+++ b/metropolis/test/e2e/BUILD.bazel
@@ -40,7 +40,6 @@
     rundir = ".",
     deps = [
         "//metropolis/node",
-        "//metropolis/node/core/identity",
         "//metropolis/node/core/rpc",
         "//metropolis/pkg/localregistry",
         "//metropolis/proto/api",
diff --git a/metropolis/test/e2e/main_test.go b/metropolis/test/e2e/main_test.go
index 7004f7b..d4b8227 100644
--- a/metropolis/test/e2e/main_test.go
+++ b/metropolis/test/e2e/main_test.go
@@ -44,7 +44,6 @@
 	apb "source.monogon.dev/metropolis/proto/api"
 
 	common "source.monogon.dev/metropolis/node"
-	"source.monogon.dev/metropolis/node/core/identity"
 	"source.monogon.dev/metropolis/node/core/rpc"
 	"source.monogon.dev/metropolis/pkg/localregistry"
 	"source.monogon.dev/metropolis/test/launch"
@@ -129,7 +128,7 @@
 		addresses := make(map[string]bool)
 		for _, n := range nodes {
 			if len(n.Addresses) != 1 {
-				return fmt.Errorf("node %s has no addresss", identity.NodeID(n.PublicKey))
+				return fmt.Errorf("node %s has no addresss", n.Id)
 			}
 			address := n.Addresses[0].Host
 			addresses[address] = true