diff --git a/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-processors/src/main/java/org/apache/nifi/processors/pgp/DecryptContentPGP.java b/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-processors/src/main/java/org/apache/nifi/processors/pgp/DecryptContentPGP.java
index 048d483b9c01..72a510eccf55 100644
--- a/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-processors/src/main/java/org/apache/nifi/processors/pgp/DecryptContentPGP.java
+++ b/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-processors/src/main/java/org/apache/nifi/processors/pgp/DecryptContentPGP.java
@@ -38,7 +38,7 @@
 import org.apache.nifi.processors.pgp.attributes.DecryptionStrategy;
 import org.apache.nifi.processors.pgp.exception.PGPDecryptionException;
 import org.apache.nifi.processors.pgp.exception.PGPProcessException;
-import org.apache.nifi.processors.pgp.io.KeyIdentifierConverter;
+import org.apache.nifi.pgp.service.api.KeyIdentifierConverter;
 import org.apache.nifi.stream.io.StreamUtils;
 
 import org.apache.nifi.util.StringUtils;
diff --git a/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-processors/src/main/java/org/apache/nifi/processors/pgp/SignContentPGP.java b/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-processors/src/main/java/org/apache/nifi/processors/pgp/SignContentPGP.java
index 87726fa7d2cf..e965edb45e3f 100644
--- a/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-processors/src/main/java/org/apache/nifi/processors/pgp/SignContentPGP.java
+++ b/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-processors/src/main/java/org/apache/nifi/processors/pgp/SignContentPGP.java
@@ -39,7 +39,7 @@
 import org.apache.nifi.processors.pgp.attributes.SigningStrategy;
 import org.apache.nifi.processors.pgp.exception.PGPProcessException;
 import org.apache.nifi.processors.pgp.io.EncodingStreamCallback;
-import org.apache.nifi.processors.pgp.io.KeyIdentifierConverter;
+import org.apache.nifi.pgp.service.api.KeyIdentifierConverter;
 import org.bouncycastle.openpgp.PGPException;
 import org.bouncycastle.openpgp.PGPLiteralDataGenerator;
 import org.bouncycastle.openpgp.PGPOnePassSignature;
diff --git a/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-processors/src/main/java/org/apache/nifi/processors/pgp/VerifyContentPGP.java b/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-processors/src/main/java/org/apache/nifi/processors/pgp/VerifyContentPGP.java
index 115ffddab3d6..d932d3fc200a 100644
--- a/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-processors/src/main/java/org/apache/nifi/processors/pgp/VerifyContentPGP.java
+++ b/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-processors/src/main/java/org/apache/nifi/processors/pgp/VerifyContentPGP.java
@@ -31,7 +31,7 @@
 import org.apache.nifi.processor.Relationship;
 import org.apache.nifi.processor.io.StreamCallback;
 import org.apache.nifi.processors.pgp.exception.PGPProcessException;
-import org.apache.nifi.processors.pgp.io.KeyIdentifierConverter;
+import org.apache.nifi.pgp.service.api.KeyIdentifierConverter;
 import org.apache.nifi.stream.io.StreamUtils;
 import org.bouncycastle.openpgp.PGPCompressedData;
 import org.bouncycastle.openpgp.PGPException;
diff --git a/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-processors/src/test/java/org/apache/nifi/processors/pgp/EncryptContentPGPTest.java b/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-processors/src/test/java/org/apache/nifi/processors/pgp/EncryptContentPGPTest.java
index 34a845f0133b..acfd413184c4 100644
--- a/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-processors/src/test/java/org/apache/nifi/processors/pgp/EncryptContentPGPTest.java
+++ b/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-processors/src/test/java/org/apache/nifi/processors/pgp/EncryptContentPGPTest.java
@@ -21,7 +21,7 @@
 import org.apache.nifi.processors.pgp.attributes.DecryptionStrategy;
 import org.apache.nifi.processors.pgp.attributes.FileEncoding;
 import org.apache.nifi.processors.pgp.attributes.SymmetricKeyAlgorithm;
-import org.apache.nifi.processors.pgp.io.KeyIdentifierConverter;
+import org.apache.nifi.pgp.service.api.KeyIdentifierConverter;
 import org.apache.nifi.reporting.InitializationException;
 import org.apache.nifi.stream.io.StreamUtils;
 import org.apache.nifi.util.MockFlowFile;
diff --git a/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-processors/src/test/java/org/apache/nifi/processors/pgp/SignContentPGPTest.java b/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-processors/src/test/java/org/apache/nifi/processors/pgp/SignContentPGPTest.java
index 81cff89c0183..0baada4a89a4 100644
--- a/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-processors/src/test/java/org/apache/nifi/processors/pgp/SignContentPGPTest.java
+++ b/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-processors/src/test/java/org/apache/nifi/processors/pgp/SignContentPGPTest.java
@@ -21,7 +21,7 @@
 import org.apache.nifi.processors.pgp.attributes.FileEncoding;
 import org.apache.nifi.processors.pgp.attributes.HashAlgorithm;
 import org.apache.nifi.processors.pgp.attributes.SigningStrategy;
-import org.apache.nifi.processors.pgp.io.KeyIdentifierConverter;
+import org.apache.nifi.pgp.service.api.KeyIdentifierConverter;
 import org.apache.nifi.reporting.InitializationException;
 import org.apache.nifi.util.LogMessage;
 import org.apache.nifi.util.MockFlowFile;
diff --git a/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-processors/src/test/java/org/apache/nifi/processors/pgp/VerifyContentPGPTest.java b/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-processors/src/test/java/org/apache/nifi/processors/pgp/VerifyContentPGPTest.java
index 33e74c347e7d..a5b5e54af577 100644
--- a/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-processors/src/test/java/org/apache/nifi/processors/pgp/VerifyContentPGPTest.java
+++ b/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-processors/src/test/java/org/apache/nifi/processors/pgp/VerifyContentPGPTest.java
@@ -20,7 +20,7 @@
 import org.apache.nifi.pgp.util.PGPFileUtils;
 import org.apache.nifi.pgp.util.PGPSecretKeyGenerator;
 import org.apache.nifi.pgp.util.PGPOperationUtils;
-import org.apache.nifi.processors.pgp.io.KeyIdentifierConverter;
+import org.apache.nifi.pgp.service.api.KeyIdentifierConverter;
 import org.apache.nifi.reporting.InitializationException;
 import org.apache.nifi.util.LogMessage;
 import org.apache.nifi.util.MockFlowFile;
diff --git a/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-processors/src/main/java/org/apache/nifi/processors/pgp/io/KeyIdentifierConverter.java b/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-service-api/src/main/java/org/apache/nifi/pgp/service/api/KeyIdentifierConverter.java
similarity index 91%
rename from nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-processors/src/main/java/org/apache/nifi/processors/pgp/io/KeyIdentifierConverter.java
rename to nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-service-api/src/main/java/org/apache/nifi/pgp/service/api/KeyIdentifierConverter.java
index 25e5d916f9e1..abee47e1b511 100644
--- a/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-processors/src/main/java/org/apache/nifi/processors/pgp/io/KeyIdentifierConverter.java
+++ b/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-service-api/src/main/java/org/apache/nifi/pgp/service/api/KeyIdentifierConverter.java
@@ -14,7 +14,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.apache.nifi.processors.pgp.io;
+package org.apache.nifi.pgp.service.api;
 
 import java.math.BigInteger;
 
@@ -24,6 +24,8 @@
 public class KeyIdentifierConverter {
     private static final int HEXADECIMAL_RADIX = 16;
 
+    private static final String KEY_ID_FORMAT = "%016X";
+
     /**
      * Format numeric key identifier as uppercase hexadecimal string
      *
@@ -31,7 +33,7 @@ public class KeyIdentifierConverter {
      * @return Uppercase hexadecimal string
      */
     public static String format(final long keyId) {
-        return Long.toHexString(keyId).toUpperCase();
+        return String.format(KEY_ID_FORMAT, keyId);
     }
 
     /**
diff --git a/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-processors/src/test/java/org/apache/nifi/processors/pgp/io/KeyIdentifierConverterTest.java b/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-service-api/src/test/java/org/apache/nifi/pgp/service/api/KeyIdentifierConverterTest.java
similarity index 97%
rename from nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-processors/src/test/java/org/apache/nifi/processors/pgp/io/KeyIdentifierConverterTest.java
rename to nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-service-api/src/test/java/org/apache/nifi/pgp/service/api/KeyIdentifierConverterTest.java
index 7c047b31f97a..76b76811a095 100644
--- a/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-processors/src/test/java/org/apache/nifi/processors/pgp/io/KeyIdentifierConverterTest.java
+++ b/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-service-api/src/test/java/org/apache/nifi/pgp/service/api/KeyIdentifierConverterTest.java
@@ -14,7 +14,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.apache.nifi.processors.pgp.io;
+package org.apache.nifi.pgp.service.api;
 
 import org.junit.jupiter.api.Test;
 
diff --git a/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-service/src/main/java/org/apache/nifi/pgp/service/standard/StandardPGPPrivateKeyService.java b/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-service/src/main/java/org/apache/nifi/pgp/service/standard/StandardPGPPrivateKeyService.java
index d43bfa8a7a21..c1251e5e098b 100644
--- a/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-service/src/main/java/org/apache/nifi/pgp/service/standard/StandardPGPPrivateKeyService.java
+++ b/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-service/src/main/java/org/apache/nifi/pgp/service/standard/StandardPGPPrivateKeyService.java
@@ -27,6 +27,7 @@
 import org.apache.nifi.controller.AbstractControllerService;
 import org.apache.nifi.controller.ConfigurationContext;
 import org.apache.nifi.expression.ExpressionLanguageScope;
+import org.apache.nifi.pgp.service.api.KeyIdentifierConverter;
 import org.apache.nifi.pgp.service.api.PGPPrivateKeyService;
 import org.apache.nifi.pgp.service.standard.exception.PGPConfigurationException;
 import org.apache.nifi.processor.util.StandardValidators;
@@ -142,7 +143,7 @@ public void onDisabled() {
      */
     @Override
     public Optional<PGPPrivateKey> findPrivateKey(final long keyIdentifier) {
-        getLogger().debug("Find Private Key [{}]", Long.toHexString(keyIdentifier).toUpperCase());
+        getLogger().debug("Find Private Key [{}]", KeyIdentifierConverter.format(keyIdentifier));
         return Optional.ofNullable(privateKeys.get(keyIdentifier));
     }
 
@@ -256,7 +257,7 @@ private List<PGPPrivateKey> extractPrivateKeys(final PGPSecretKeyRingCollection
         for (final PGPSecretKeyRing keyRing : keyRings) {
             for (final PGPSecretKey secretKey : keyRing) {
                 final long keyId = secretKey.getKeyID();
-                final String keyIdentifier = Long.toHexString(keyId).toUpperCase();
+                final String keyIdentifier = KeyIdentifierConverter.format(keyId);
                 try {
                     final PGPPrivateKey privateKey = secretKey.extractPrivateKey(keyDecryptor);
                     extractedPrivateKeys.add(privateKey);
diff --git a/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-service/src/main/java/org/apache/nifi/pgp/service/standard/StandardPGPPublicKeyService.java b/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-service/src/main/java/org/apache/nifi/pgp/service/standard/StandardPGPPublicKeyService.java
index 880ff222b1c9..0aac1c2b14d1 100644
--- a/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-service/src/main/java/org/apache/nifi/pgp/service/standard/StandardPGPPublicKeyService.java
+++ b/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-service/src/main/java/org/apache/nifi/pgp/service/standard/StandardPGPPublicKeyService.java
@@ -27,6 +27,7 @@
 import org.apache.nifi.controller.AbstractControllerService;
 import org.apache.nifi.controller.ConfigurationContext;
 import org.apache.nifi.expression.ExpressionLanguageScope;
+import org.apache.nifi.pgp.service.api.KeyIdentifierConverter;
 import org.apache.nifi.pgp.service.api.PGPPublicKeyService;
 import org.apache.nifi.pgp.service.standard.exception.PGPConfigurationException;
 import org.apache.nifi.processor.util.StandardValidators;
@@ -186,7 +187,7 @@ protected Collection<ValidationResult> customValidate(final ValidationContext co
 
     private boolean isPublicKeyMatched(final PGPPublicKey publicKey, final String search) {
         boolean matched = false;
-        final String keyId = Long.toHexString(publicKey.getKeyID()).toUpperCase();
+        final String keyId = KeyIdentifierConverter.format(publicKey.getKeyID());
         if (keyId.equals(search)) {
             matched = true;
         } else {
diff --git a/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-service/src/test/java/org/apche/nifi/pgp/service/standard/StandardPGPPublicKeyServiceTest.java b/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-service/src/test/java/org/apche/nifi/pgp/service/standard/StandardPGPPublicKeyServiceTest.java
index a0a6f76b7447..10268f0c5434 100644
--- a/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-service/src/test/java/org/apche/nifi/pgp/service/standard/StandardPGPPublicKeyServiceTest.java
+++ b/nifi-nar-bundles/nifi-pgp-bundle/nifi-pgp-service/src/test/java/org/apche/nifi/pgp/service/standard/StandardPGPPublicKeyServiceTest.java
@@ -16,6 +16,7 @@
  */
 package org.apche.nifi.pgp.service.standard;
 
+import org.apache.nifi.pgp.service.api.KeyIdentifierConverter;
 import org.apache.nifi.pgp.service.standard.StandardPGPPublicKeyService;
 import org.apache.nifi.pgp.util.PGPFileUtils;
 import org.apache.nifi.pgp.util.PGPSecretKeyGenerator;
@@ -129,7 +130,7 @@ public void testFindPublicKeyBinaryKeyringFileAndAsciiKeyring() throws Exception
 
     private void assertPublicKeyFound(final PGPSecretKey secretKey) {
         final long keyIdentifier = secretKey.getKeyID();
-        final String publicKeySearch = Long.toHexString(keyIdentifier).toUpperCase();
+        final String publicKeySearch = KeyIdentifierConverter.format(keyIdentifier);
         final Optional<PGPPublicKey> optionalPublicKey = service.findPublicKey(publicKeySearch);
         assertTrue(optionalPublicKey.isPresent());
         final PGPPublicKey publicKey = optionalPublicKey.get();