diff --git a/kernel/kernel-keymanager-service/src/main/java/io/mosip/kernel/signature/service/impl/CoseSignatureServiceImpl.java b/kernel/kernel-keymanager-service/src/main/java/io/mosip/kernel/signature/service/impl/CoseSignatureServiceImpl.java
index a2b2e3a3..f683409b 100644
--- a/kernel/kernel-keymanager-service/src/main/java/io/mosip/kernel/signature/service/impl/CoseSignatureServiceImpl.java
+++ b/kernel/kernel-keymanager-service/src/main/java/io/mosip/kernel/signature/service/impl/CoseSignatureServiceImpl.java
@@ -385,8 +385,9 @@ public String getKeyId(String kidPrepend, SignatureCertificate certificateRespon
                 (requestDto.getUnprotectedHeader() != null && requestDto.getUnprotectedHeader().containsKey(SignatureConstant.COSE_HEADER_KID))) {
             String kidPrefix = kidPrepend;
             if (kidPrepend.equalsIgnoreCase(SignatureConstant.KEY_ID_PREFIX)) {
-                String payload = Objects.isNull(requestDto.getPayload()) ? "" : requestDto.getPayload();
-                kidPrefix = SignatureUtil.getIssuerFromPayload(payload);
+                String payload = Objects.isNull(requestDto.getPayload()) ? SignatureConstant.BLANK : requestDto.getPayload();
+                String jsonData = SignatureUtil.isDataValid(payload) ? (new String(CryptoUtil.decodeURLSafeBase64(payload))) : SignatureConstant.BLANK;
+                kidPrefix = SignatureUtil.getIssuerFromPayload(jsonData);
                 if (kidPrefix.isEmpty())
                     kidPrefix = SignatureConstant.BLANK;
                 else
diff --git a/kernel/kernel-keymanager-service/src/main/java/io/mosip/kernel/signature/util/SignatureUtil.java b/kernel/kernel-keymanager-service/src/main/java/io/mosip/kernel/signature/util/SignatureUtil.java
index c31c6529..59ef5dc1 100644
--- a/kernel/kernel-keymanager-service/src/main/java/io/mosip/kernel/signature/util/SignatureUtil.java
+++ b/kernel/kernel-keymanager-service/src/main/java/io/mosip/kernel/signature/util/SignatureUtil.java
@@ -232,7 +232,7 @@ public static String getIssuerFromPayload(String jsonPayload) {
 				return SignatureConstant.BLANK;
 			}
 
-			JsonNode jsonNode = mapper.readTree(new String(CryptoUtil.decodeURLSafeBase64(jsonPayload)));
+			JsonNode jsonNode = mapper.readTree(jsonPayload);
 
 			if (jsonNode.has(SignatureConstant.ISSUER)) {
 				return jsonNode.get(SignatureConstant.ISSUER).asText();
diff --git a/kernel/kernel-keymanager-service/src/test/java/io/mosip/kernel/signature/test/Util/SignatureUtilTest.java b/kernel/kernel-keymanager-service/src/test/java/io/mosip/kernel/signature/test/Util/SignatureUtilTest.java
index 6562b76e..d7e6ac78 100644
--- a/kernel/kernel-keymanager-service/src/test/java/io/mosip/kernel/signature/test/Util/SignatureUtilTest.java
+++ b/kernel/kernel-keymanager-service/src/test/java/io/mosip/kernel/signature/test/Util/SignatureUtilTest.java
@@ -154,16 +154,14 @@ public void testGetSignAlgorithm() {
 
     @Test
     public void testGetIssuerFromPayload() {
-        // getIssuerFromPayload expects URL-safe Base64 encoded JSON payload
-        String payload = CryptoUtil.encodeToURLSafeBase64("{\"iss\":\"test-issuer\",\"data\":\"value\"}".getBytes());
+        String payload = "{\"iss\":\"test-issuer\",\"data\":\"value\"}";
         String issuer = SignatureUtil.getIssuerFromPayload(payload);
         Assert.assertEquals("test-issuer", issuer);
 
-        String noIssuer = SignatureUtil.getIssuerFromPayload(CryptoUtil.encodeToURLSafeBase64("{\"data\":\"value\"}".getBytes()));
+        String noIssuer = SignatureUtil.getIssuerFromPayload("{\"data\":\"value\"}");
         Assert.assertEquals("", noIssuer);
 
-        // Test with invalid base64-encoded JSON (malformed JSON after decoding)
-        String invalidJson = SignatureUtil.getIssuerFromPayload(CryptoUtil.encodeToURLSafeBase64("invalid json".getBytes()));
+        String invalidJson = SignatureUtil.getIssuerFromPayload("invalid json");
         Assert.assertEquals("", invalidJson);
     }