diff --git a/org.eclipse.jgit.http.server/src/org/eclipse/jgit/http/server/ServletUtils.java b/org.eclipse.jgit.http.server/src/org/eclipse/jgit/http/server/ServletUtils.java
index b6d73b559..256279bfe 100644
--- a/org.eclipse.jgit.http.server/src/org/eclipse/jgit/http/server/ServletUtils.java
+++ b/org.eclipse.jgit.http.server/src/org/eclipse/jgit/http/server/ServletUtils.java
@@ -64,7 +64,6 @@
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
-import org.eclipse.jgit.internal.storage.dfs.DfsRepository;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.Repository;
@@ -276,12 +275,11 @@ private static String etag(byte[] content) {
 	}
 
 	static String identify(Repository git) {
-		if (git instanceof DfsRepository) {
-			return ((DfsRepository) git).getDescription().getRepositoryName();
-		} else if (git.getDirectory() != null) {
-			return git.getDirectory().getPath();
+		String identifier = git.getIdentifier();
+		if (identifier == null) {
+			return "unknown";
 		}
-		return "unknown";
+		return identifier;
 	}
 
 	private ServletUtils() {
diff --git a/org.eclipse.jgit/.settings/.api_filters b/org.eclipse.jgit/.settings/.api_filters
index dc1df5963..7f93191ca 100644
--- a/org.eclipse.jgit/.settings/.api_filters
+++ b/org.eclipse.jgit/.settings/.api_filters
@@ -22,6 +22,14 @@
             </message_arguments>
         </filter>
     </resource>
+    <resource path="src/org/eclipse/jgit/lib/Repository.java" type="org.eclipse.jgit.lib.Repository">
+        <filter id="336695337">
+            <message_arguments>
+                <message_argument value="org.eclipse.jgit.lib.Repository"/>
+                <message_argument value="getIdentifier()"/>
+            </message_arguments>
+        </filter>
+    </resource>
     <resource path="src/org/eclipse/jgit/revwalk/ObjectWalk.java" type="org.eclipse.jgit.revwalk.ObjectWalk">
         <filter comment="ignore the risk subclasses could define the same field and cause a name clash" id="336658481">
             <message_arguments>
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsRepository.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsRepository.java
index 5169e929e..8e5c5a7f7 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsRepository.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsRepository.java
@@ -124,6 +124,12 @@ public StoredConfig getConfig() {
 		return config;
 	}
 
+	/** {@inheritDoc} */
+	@Override
+	public String getIdentifier() {
+		return getDescription().getRepositoryName();
+	}
+
 	/** {@inheritDoc} */
 	@Override
 	public void scanForRepoChanges() throws IOException {
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/FileRepository.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/FileRepository.java
index d82d29e4c..90772970a 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/FileRepository.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/FileRepository.java
@@ -388,6 +388,17 @@ public RefDatabase getRefDatabase() {
 		return refs;
 	}
 
+	/** {@inheritDoc} */
+	@Override
+	public String getIdentifier() {
+		File directory = getDirectory();
+		if (directory != null) {
+			return directory.getPath();
+		} else {
+			throw new IllegalStateException();
+		}
+	}
+
 	/** {@inheritDoc} */
 	@Override
 	public FileBasedConfig getConfig() {
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/lib/Repository.java b/org.eclipse.jgit/src/org/eclipse/jgit/lib/Repository.java
index aac63e9d2..d53b0c926 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/lib/Repository.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/lib/Repository.java
@@ -239,6 +239,15 @@ public File getDirectory() {
 		return gitDir;
 	}
 
+	/**
+	 * Get repository identifier.
+	 *
+	 * @return repository identifier. The returned identifier has to be unique
+	 *         within a given Git server.
+	 * @since 5.4
+	 */
+	public abstract String getIdentifier();
+
 	/**
 	 * Get the object database which stores this repository's data.
 	 *
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/transport/HMACSHA1NonceGenerator.java b/org.eclipse.jgit/src/org/eclipse/jgit/transport/HMACSHA1NonceGenerator.java
index 53eaa6a7f..01f6fec7e 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/transport/HMACSHA1NonceGenerator.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/transport/HMACSHA1NonceGenerator.java
@@ -45,14 +45,12 @@
 import static java.nio.charset.StandardCharsets.ISO_8859_1;
 import static java.nio.charset.StandardCharsets.UTF_8;
 
-import java.io.File;
 import java.security.InvalidKeyException;
 import java.security.NoSuchAlgorithmException;
 
 import javax.crypto.Mac;
 import javax.crypto.spec.SecretKeySpec;
 
-import org.eclipse.jgit.internal.storage.dfs.DfsRepository;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.transport.PushCertificate.NonceStatus;
 
@@ -87,19 +85,7 @@ public HMACSHA1NonceGenerator(String seed) throws IllegalStateException {
 	@Override
 	public synchronized String createNonce(Repository repo, long timestamp)
 			throws IllegalStateException {
-		String path;
-		if (repo instanceof DfsRepository) {
-			path = ((DfsRepository) repo).getDescription().getRepositoryName();
-		} else {
-			File directory = repo.getDirectory();
-			if (directory != null) {
-				path = directory.getPath();
-			} else {
-				throw new IllegalStateException();
-			}
-		}
-
-		String input = path + ":" + String.valueOf(timestamp); //$NON-NLS-1$
+		String input = repo.getIdentifier() + ":" + String.valueOf(timestamp); //$NON-NLS-1$
 		byte[] rawHmac = mac.doFinal(input.getBytes(UTF_8));
 		return Long.toString(timestamp) + "-" + toHex(rawHmac); //$NON-NLS-1$
 	}