diff --git a/.forgejo/workflows/ci.yml b/.forgejo/workflows/ci.yml
index a6732ca..5feac00 100644
--- a/.forgejo/workflows/ci.yml
+++ b/.forgejo/workflows/ci.yml
@@ -53,6 +53,10 @@ jobs:
           timeout 15 bash -c 'until docker exec ci-dind docker version > /dev/null 2>&1; do echo "Waiting for Docker daemon inside DinD..."; sleep 5; done'
           echo "DinD container is ready"
           
+          # Install Cosign in DinD container
+          echo "Installing Cosign..."
+          docker exec ci-dind sh -c "wget -O /usr/local/bin/cosign https://github.com/sigstore/cosign/releases/latest/download/cosign-linux-amd64 && chmod +x /usr/local/bin/cosign"
+          
           # Login to Docker Registry (using HTTPS port 443)
           echo "${{ secrets.REGISTRY_PASSWORD }}" | docker exec -i ci-dind docker login ${{ secrets.CI_HOST }}:443 -u ${{ secrets.REGISTRY_USER }} --password-stdin
           
@@ -108,13 +112,22 @@ jobs:
               # Tag for Docker Registry
               docker exec ci-dind docker tag "$image" "$registry_image"
               
-              # Push to Docker Registry
-              if docker exec ci-dind docker push "$registry_image"; then
-                echo "✓ Successfully pushed $registry_image to Docker Registry"
-              else
-                echo "✗ Failed to push $registry_image to Docker Registry"
-                exit 1
-              fi
+                      # Push to Docker Registry
+        if docker exec ci-dind docker push "$registry_image"; then
+          echo "✓ Successfully pushed $registry_image to Docker Registry"
+          
+          # Sign the image with Cosign (keyless OIDC)
+          echo "Signing image with Cosign..."
+          if docker exec ci-dind sh -c "COSIGN_EXPERIMENTAL=1 cosign sign --keyless $registry_image"; then
+            echo "✓ Successfully signed $registry_image with Cosign"
+          else
+            echo "✗ Failed to sign $registry_image with Cosign"
+            exit 1
+          fi
+        else
+          echo "✗ Failed to push $registry_image to Docker Registry"
+          exit 1
+        fi
             else
               echo "✗ Failed to pull $image from Docker Hub"
               exit 1
@@ -251,6 +264,10 @@ jobs:
           --cache-to type=gha,mode=max \
           -f /workspace/backend/Dockerfile \
           /workspace/backend
+        
+        # Sign the backend image with Cosign (keyless OIDC)
+        echo "Signing backend image with Cosign..."
+        docker exec ci-dind sh -c "COSIGN_EXPERIMENTAL=1 cosign sign --keyless ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}/backend:${{ gitea.sha }}"
 
     - name: Build and push frontend image
       run: |
@@ -263,6 +280,10 @@ jobs:
           --cache-to type=gha,mode=max \
           -f /workspace/frontend/Dockerfile \
           /workspace/frontend
+        
+        # Sign the frontend image with Cosign (keyless OIDC)
+        echo "Signing frontend image with Cosign..."
+        docker exec ci-dind sh -c "COSIGN_EXPERIMENTAL=1 cosign sign --keyless ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}/frontend:${{ gitea.sha }}"
 
     - name: Cleanup Testing Environment
       if: always()
@@ -334,6 +355,11 @@ jobs:
         
         # Wait for Docker to be ready
         timeout 30 bash -c 'until docker info; do sleep 1; done'
+        
+        # Verify signed images before deployment
+        echo "Verifying signed images..."
+        cosign verify --key /etc/containers/keys/org-cosign.pub ${{ secrets.CI_HOST }}:443/${{ secrets.APP_NAME || 'sharenet' }}/backend:${{ gitea.sha }}
+        cosign verify --key /etc/containers/keys/org-cosign.pub ${{ secrets.CI_HOST }}:443/${{ secrets.APP_NAME || 'sharenet' }}/frontend:${{ gitea.sha }}
 
     - name: Validate migration files
       run: |
diff --git a/.gitignore b/.gitignore
index a28d49e..ef8fb5a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -38,6 +38,16 @@ yarn-error.log*
 Thumbs.db
 *.pem
 
+# Cosign keys and certificates
+*.key
+*.pem
+*.crt
+*.pub
+cosign.key
+cosign.pub
+org-cosign.key
+org-cosign.pub
+
 # Build outputs
 dist/
 build/
diff --git a/CI_CD_PIPELINE_SETUP_GUIDE.md b/CI_CD_PIPELINE_SETUP_GUIDE.md
index 312a37c..88488f6 100644
--- a/CI_CD_PIPELINE_SETUP_GUIDE.md
+++ b/CI_CD_PIPELINE_SETUP_GUIDE.md
@@ -1808,8 +1808,8 @@ Go to your Forgejo repository and add these secrets in **Settings → Secrets an
 - `POSTGRES_PASSWORD`: A strong password for the PostgreSQL database
 - `REGISTRY_CLIENT_CERT`: Path to client certificate for mTLS authentication (e.g., `/etc/registry/certs/clients/client.crt`)
 - `REGISTRY_CLIENT_KEY`: Path to client private key for mTLS authentication (e.g., `/etc/registry/certs/private/client.key`)
-- `REGISTRY_PUSH_URL`: Docker Registry v2 URL for authenticated pushes (e.g., `YOUR_CI_CD_IP:4443`)
-- `REGISTRY_PULL_URL`: Docker Registry v2 URL for unauthenticated pulls (e.g., `YOUR_CI_CD_IP`)
+
+**Note**: The CI pipeline now uses mTLS authentication for pushes (port 4443) and Cosign for image signing. The registry policy enforces Sigstore signatures for all images consumed from the registry.
 
 
 
diff --git a/Docker_Registry_Install_Guide.md b/Docker_Registry_Install_Guide.md
index c964401..e704234 100644
--- a/Docker_Registry_Install_Guide.md
+++ b/Docker_Registry_Install_Guide.md
@@ -382,6 +382,23 @@ sudo cp /etc/registry/certs/ca/ca.crt /usr/local/share/ca-certificates/registry-
 
 # This step should complete with "1 added, 0 removed". If it does not, there could be a problem with the certificate you generated, or you might already have a certificate in the trust store
 sudo update-ca-certificates
+
+# 4. Generate Cosign key pair for image signing
+# Install Cosign if not already installed
+wget -O /usr/local/bin/cosign https://github.com/sigstore/cosign/releases/latest/download/cosign-linux-amd64
+chmod +x /usr/local/bin/cosign
+
+# Generate Cosign key pair (or use keyless OIDC in CI)
+cosign generate-key-pair
+
+# Create directory for Cosign public key distribution
+sudo mkdir -p /etc/containers/keys
+sudo cp cosign.pub /etc/containers/keys/org-cosign.pub
+sudo chmod 644 /etc/containers/keys/org-cosign.pub
+
+# Secure the private key (keep this safe and distribute to CI systems)
+sudo chmod 600 cosign.key
+echo "IMPORTANT: Secure cosign.key and distribute to CI systems for image signing"
 ```
 
 ## Step 4: Configure Firewall and Start Services
@@ -410,13 +427,17 @@ sudo ufw allow from 192.168.0.0/16 to any port 4443 proto tcp
 
 ## Client Trust Configuration
 
-For clients to trust your registry certificates, they should install the server CA certificate:
+For clients to trust your registry certificates and enforce image signatures, they should install the server CA certificate and Cosign public key:
 
 **For pulls (port 443):**
 ```bash
 # On client systems - use the actual FQDN/IP from your certificates
 sudo mkdir -p /etc/containers/certs.d/REGISTRY_HOST
 sudo cp /path/to/registry-ca.crt /etc/containers/certs.d/REGISTRY_HOST/ca.crt
+
+# Install Cosign public key for signature verification
+sudo mkdir -p /etc/containers/keys
+sudo cp /path/to/org-cosign.pub /etc/containers/keys/org-cosign.pub
 ```
 
 **For pushes (port 4443, mTLS):**
@@ -426,9 +447,23 @@ sudo mkdir -p /etc/containers/certs.d/REGISTRY_HOST:4443
 sudo cp /path/to/registry-ca.crt /etc/containers/certs.d/REGISTRY_HOST:4443/ca.crt
 sudo cp /path/to/client.crt /etc/containers/certs.d/REGISTRY_HOST:4443/client.cert
 sudo cp /path/to/client.key /etc/containers/certs.d/REGISTRY_HOST:4443/client.key
+
+# Install Cosign public key for signature verification
+sudo mkdir -p /etc/containers/keys
+sudo cp /path/to/org-cosign.pub /etc/containers/keys/org-cosign.pub
 ```
 
-**Note:** Replace `REGISTRY_HOST` with the actual FQDN or IP address that matches your certificate's Subject Alternative Name (SAN). For pushes, both the server CA certificate and client certificate/key are required for mTLS authentication.
+**Note:** Replace `REGISTRY_HOST` with the actual FQDN or IP address that matches your certificate's Subject Alternative Name (SAN). For pushes, both the server CA certificate and client certificate/key are required for mTLS authentication. The Cosign public key is required for signature verification on both ports.
+
+## Security Model
+
+This setup implements a multi-layered security approach:
+
+1. **mTLS on port 4443**: Controls **who can push** to the registry
+2. **Cosign signatures**: Controls **what content is trusted** - all images must be signed
+3. **Policy enforcement**: The `containers-policy.json` rejects unsigned images from the registry
+4. **Port separation**: Unauthenticated pulls (443) vs authenticated pushes (4443)
+5. **Rootless registry**: Registry runs as non-root user with minimal privileges
 ```
 
 ### 4.2 Enable and Start Services
@@ -548,6 +583,10 @@ openssl s_client -connect YOUR_ACTUAL_IP_ADDRESS:4443 -servername YOUR_ACTUAL_IP
   -cert /etc/registry/certs/clients/client.crt \
   -key /etc/registry/certs/private/client.key < /dev/null
 
+# Test Cosign signature verification
+echo "Testing Cosign signature verification..."
+cosign verify --key /etc/containers/keys/org-cosign.pub YOUR_ACTUAL_IP_ADDRESS/APP_NAME/test:latest
+
 # Verify nginx is using the correct certificates
 sudo ls -la /etc/registry/certs/registry.crt /etc/registry/certs/private/registry.key /etc/registry/certs/clients/ca.crt
 
diff --git a/registry/containers-policy.json b/registry/containers-policy.json
index f44727a..2467b3e 100644
--- a/registry/containers-policy.json
+++ b/registry/containers-policy.json
@@ -1,19 +1,19 @@
 {
-  "default": [
-    {
-      "type": "reject"
-    }
-  ],
+  "default": [{ "type": "reject" }],
   "transports": {
     "docker": {
-      "localhost:443": [
+      "REGISTRY_HOST": [
         {
-          "type": "insecureAcceptAnything"
+          "type": "sigstoreSigned",
+          "keyPath": "/etc/containers/keys/org-cosign.pub",
+          "signedIdentity": { "type": "matchRepository" }
         }
       ],
-      "localhost:4443": [
+      "REGISTRY_HOST:4443": [
         {
-          "type": "insecureAcceptAnything"
+          "type": "sigstoreSigned",
+          "keyPath": "/etc/containers/keys/org-cosign.pub",
+          "signedIdentity": { "type": "matchRepository" }
         }
       ],
       "docker.io": [
@@ -22,12 +22,6 @@
         }
       ]
     },
-    "docker-daemon": {
-      "": [
-        {
-          "type": "insecureAcceptAnything"
-        }
-      ]
-    }
+    "docker-daemon": { "": [{ "type": "reject" }] }
   }
 }