diff --git a/inventory.titan-rpi4.yaml b/inventory.titan-rpi4.yaml
index 83614bf..dd14fde 100644
--- a/inventory.titan-rpi4.yaml
+++ b/inventory.titan-rpi4.yaml
@@ -74,7 +74,7 @@ nodes:
     k3s_token: ${METIS_K3S_TOKEN}
     ssh_user: atlas
     ssh_authorized_keys:
-      - ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOb8oMX6u0z3sH/p/WBGlvPXXdbGETCKzWYwR/dd6fZb titan-bastion
+      - ${METIS_SSH_KEY_BASTION}
   - name: titan-05
     class: rpi5-ubuntu-worker
     hostname: titan-05
@@ -84,7 +84,7 @@ nodes:
     k3s_token: ${METIS_K3S_TOKEN}
     ssh_user: atlas
     ssh_authorized_keys:
-      - ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOb8oMX6u0z3sH/p/WBGlvPXXdbGETCKzWYwR/dd6fZb titan-bastion
+      - ${METIS_SSH_KEY_BASTION}
   - name: titan-06
     class: rpi5-ubuntu-worker
     hostname: titan-06
@@ -94,7 +94,7 @@ nodes:
     k3s_token: ${METIS_K3S_TOKEN}
     ssh_user: atlas
     ssh_authorized_keys:
-      - ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOb8oMX6u0z3sH/p/WBGlvPXXdbGETCKzWYwR/dd6fZb titan-bastion
+      - ${METIS_SSH_KEY_BASTION}
   - name: titan-07
     class: rpi5-ubuntu-worker
     hostname: titan-07
@@ -104,7 +104,7 @@ nodes:
     k3s_token: ${METIS_K3S_TOKEN}
     ssh_user: atlas
     ssh_authorized_keys:
-      - ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOb8oMX6u0z3sH/p/WBGlvPXXdbGETCKzWYwR/dd6fZb titan-bastion
+      - ${METIS_SSH_KEY_BASTION}
   - name: titan-08
     class: rpi5-ubuntu-worker
     hostname: titan-08
@@ -114,7 +114,7 @@ nodes:
     k3s_token: ${METIS_K3S_TOKEN}
     ssh_user: atlas
     ssh_authorized_keys:
-      - ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOb8oMX6u0z3sH/p/WBGlvPXXdbGETCKzWYwR/dd6fZb titan-bastion
+      - ${METIS_SSH_KEY_BASTION}
   - name: titan-09
     class: rpi5-ubuntu-worker
     hostname: titan-09
@@ -124,7 +124,7 @@ nodes:
     k3s_token: ${METIS_K3S_TOKEN}
     ssh_user: atlas
     ssh_authorized_keys:
-      - ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOb8oMX6u0z3sH/p/WBGlvPXXdbGETCKzWYwR/dd6fZb titan-bastion
+      - ${METIS_SSH_KEY_BASTION}
   - name: titan-10
     class: rpi5-ubuntu-worker
     hostname: titan-10
@@ -134,7 +134,7 @@ nodes:
     k3s_token: ${METIS_K3S_TOKEN}
     ssh_user: atlas
     ssh_authorized_keys:
-      - ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOb8oMX6u0z3sH/p/WBGlvPXXdbGETCKzWYwR/dd6fZb titan-bastion
+      - ${METIS_SSH_KEY_BASTION}
   - name: titan-11
     class: rpi5-ubuntu-worker
     hostname: titan-11
@@ -144,7 +144,7 @@ nodes:
     k3s_token: ${METIS_K3S_TOKEN}
     ssh_user: atlas
     ssh_authorized_keys:
-      - ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOb8oMX6u0z3sH/p/WBGlvPXXdbGETCKzWYwR/dd6fZb titan-bastion
+      - ${METIS_SSH_KEY_BASTION}
   - name: titan-12
     class: rpi4-armbian-worker
     hostname: titan-12
@@ -154,7 +154,7 @@ nodes:
     k3s_token: ${METIS_K3S_TOKEN}
     ssh_user: atlas
     ssh_authorized_keys:
-      - ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOb8oMX6u0z3sH/p/WBGlvPXXdbGETCKzWYwR/dd6fZb titan-bastion
+      - ${METIS_SSH_KEY_BASTION}
   - name: titan-16
     class: rpi4-armbian-worker
     hostname: titan-16
@@ -164,7 +164,7 @@ nodes:
     k3s_token: ${METIS_K3S_TOKEN}
     ssh_user: atlas
     ssh_authorized_keys:
-      - ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOb8oMX6u0z3sH/p/WBGlvPXXdbGETCKzWYwR/dd6fZb titan-bastion
+      - ${METIS_SSH_KEY_BASTION}
   - name: titan-13
     class: rpi4-armbian-longhorn
     hostname: titan-13
@@ -174,7 +174,7 @@ nodes:
     k3s_token: ${METIS_K3S_TOKEN}
     ssh_user: atlas
     ssh_authorized_keys:
-      - ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOb8oMX6u0z3sH/p/WBGlvPXXdbGETCKzWYwR/dd6fZb titan-bastion
+      - ${METIS_SSH_KEY_BASTION}
     longhorn_disks:
       - mountpoint: /mnt/astreae
         uuid: 6031fa8b-f28c-45c3-b7bc-6133300e07c6
@@ -191,7 +191,7 @@ nodes:
     k3s_token: ${METIS_K3S_TOKEN}
     ssh_user: atlas
     ssh_authorized_keys:
-      - ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOb8oMX6u0z3sH/p/WBGlvPXXdbGETCKzWYwR/dd6fZb titan-bastion
+      - ${METIS_SSH_KEY_BASTION}
     longhorn_disks:
       - mountpoint: /mnt/astreae
         uuid: f3362f14-5822-449f-944b-ac570b5cd615
@@ -208,7 +208,7 @@ nodes:
     k3s_token: ${METIS_K3S_TOKEN}
     ssh_user: atlas
     ssh_authorized_keys:
-      - ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOb8oMX6u0z3sH/p/WBGlvPXXdbGETCKzWYwR/dd6fZb titan-bastion
+      - ${METIS_SSH_KEY_BASTION}
   - name: titan-17
     class: rpi4-armbian-longhorn
     hostname: titan-17
@@ -218,7 +218,7 @@ nodes:
     k3s_token: ${METIS_K3S_TOKEN}
     ssh_user: atlas
     ssh_authorized_keys:
-      - ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOb8oMX6u0z3sH/p/WBGlvPXXdbGETCKzWYwR/dd6fZb titan-bastion
+      - ${METIS_SSH_KEY_BASTION}
     longhorn_disks:
       - mountpoint: /mnt/astreae
         uuid: 1fecdade-08b0-49cb-9ae3-be6c188b0a96
@@ -235,7 +235,7 @@ nodes:
     k3s_token: ${METIS_K3S_TOKEN}
     ssh_user: atlas
     ssh_authorized_keys:
-      - ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOb8oMX6u0z3sH/p/WBGlvPXXdbGETCKzWYwR/dd6fZb titan-bastion
+      - ${METIS_SSH_KEY_BASTION}
     longhorn_disks:
       - mountpoint: /mnt/astreae
         uuid: 4890abb9-dda2-4f4f-9c0f-081ee82849cf
@@ -252,7 +252,7 @@ nodes:
     k3s_token: ${METIS_K3S_TOKEN}
     ssh_user: atlas
     ssh_authorized_keys:
-      - ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOb8oMX6u0z3sH/p/WBGlvPXXdbGETCKzWYwR/dd6fZb titan-bastion
+      - ${METIS_SSH_KEY_BASTION}
   - name: titan-20
     class: jetson-ubuntu-accelerator
     hostname: titan-20
@@ -262,7 +262,7 @@ nodes:
     k3s_token: ${METIS_K3S_TOKEN}
     ssh_user: atlas
     ssh_authorized_keys:
-      - ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOb8oMX6u0z3sH/p/WBGlvPXXdbGETCKzWYwR/dd6fZb titan-bastion
+      - ${METIS_SSH_KEY_BASTION}
   - name: titan-21
     class: jetson-ubuntu-accelerator
     hostname: titan-21
@@ -272,7 +272,7 @@ nodes:
     k3s_token: ${METIS_K3S_TOKEN}
     ssh_user: atlas
     ssh_authorized_keys:
-      - ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOb8oMX6u0z3sH/p/WBGlvPXXdbGETCKzWYwR/dd6fZb titan-bastion
+      - ${METIS_SSH_KEY_BASTION}
   - name: titan-22
     class: amd64-debian-worker
     hostname: titan-22
@@ -282,7 +282,7 @@ nodes:
     k3s_token: ${METIS_K3S_TOKEN}
     ssh_user: atlas
     ssh_authorized_keys:
-      - ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOb8oMX6u0z3sH/p/WBGlvPXXdbGETCKzWYwR/dd6fZb titan-bastion
+      - ${METIS_SSH_KEY_BASTION}
       - ${METIS_SSH_KEY_BRAD}
   - name: titan-db
     class: rpi5-ubuntu-host
@@ -293,7 +293,7 @@ nodes:
     k3s_token: ${METIS_K3S_TOKEN}
     ssh_user: atlas
     ssh_authorized_keys:
-      - ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOb8oMX6u0z3sH/p/WBGlvPXXdbGETCKzWYwR/dd6fZb titan-bastion
+      - ${METIS_SSH_KEY_BASTION}
       - ${METIS_SSH_KEY_BRAD}
       - ${METIS_SSH_KEY_HECATE_TETHYS}
   - name: titan-24
@@ -305,7 +305,7 @@ nodes:
     k3s_token: ${METIS_K3S_TOKEN}
     ssh_user: atlas
     ssh_authorized_keys:
-      - ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOb8oMX6u0z3sH/p/WBGlvPXXdbGETCKzWYwR/dd6fZb titan-bastion
+      - ${METIS_SSH_KEY_BASTION}
       - ${METIS_SSH_KEY_BRAD}
   - name: titan-0a
     class: rpi5-ubuntu-control-plane
@@ -316,7 +316,7 @@ nodes:
     k3s_token: ${METIS_K3S_TOKEN}
     ssh_user: atlas
     ssh_authorized_keys:
-      - ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOb8oMX6u0z3sH/p/WBGlvPXXdbGETCKzWYwR/dd6fZb titan-bastion
+      - ${METIS_SSH_KEY_BASTION}
   - name: titan-0b
     class: rpi5-ubuntu-control-plane
     hostname: titan-0b
@@ -326,7 +326,7 @@ nodes:
     k3s_token: ${METIS_K3S_TOKEN}
     ssh_user: atlas
     ssh_authorized_keys:
-      - ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOb8oMX6u0z3sH/p/WBGlvPXXdbGETCKzWYwR/dd6fZb titan-bastion
+      - ${METIS_SSH_KEY_BASTION}
   - name: titan-0c
     class: rpi5-ubuntu-control-plane
     hostname: titan-0c
@@ -336,4 +336,4 @@ nodes:
     k3s_token: ${METIS_K3S_TOKEN}
     ssh_user: atlas
     ssh_authorized_keys:
-      - ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOb8oMX6u0z3sH/p/WBGlvPXXdbGETCKzWYwR/dd6fZb titan-bastion
+      - ${METIS_SSH_KEY_BASTION}
\ No newline at end of file