diff --git a/Core/Algorithms/RSFamily/RSKeys/JWTCryptoSecurity.h b/Core/Algorithms/RSFamily/RSKeys/JWTCryptoSecurity.h
index 47d631f5..6cc55ccc 100644
--- a/Core/Algorithms/RSFamily/RSKeys/JWTCryptoSecurity.h
+++ b/Core/Algorithms/RSFamily/RSKeys/JWTCryptoSecurity.h
@@ -15,7 +15,7 @@
 + (SecKeyRef)addKeyWithData:(NSData *)data asPublic:(BOOL)public tag:(NSString *)tag type:(NSString *)type error:(NSError *__autoreleasing*)error;
 + (SecKeyRef)addKeyWithData:(NSData *)data asPublic:(BOOL)public tag:(NSString *)tag error:(NSError *__autoreleasing*)error;
 + (SecKeyRef)keyByTag:(NSString *)tag error:(NSError *__autoreleasing*)error;
-+ (void)removeKeyByTag:(NSString *)tag error:(NSError *__autoreleasing*)error;
++ (BOOL)removeKeyByTag:(NSString *)tag error:(NSError *__autoreleasing*)error;
 @end
 
 @interface JWTCryptoSecurity (Certificates)
diff --git a/Core/Algorithms/RSFamily/RSKeys/JWTCryptoSecurity.m b/Core/Algorithms/RSFamily/RSKeys/JWTCryptoSecurity.m
index e65384dc..418af600 100644
--- a/Core/Algorithms/RSFamily/RSKeys/JWTCryptoSecurity.m
+++ b/Core/Algorithms/RSFamily/RSKeys/JWTCryptoSecurity.m
@@ -7,6 +7,8 @@
 //
 
 #import "JWTCryptoSecurity.h"
+#import "JWTErrorDescription.h"
+
 @interface JWTMemoryLayout : NSObject
 + (NSString *)typeUInt8;
 + (NSString *)typeCUnsignedChar;
@@ -127,18 +129,28 @@ + (SecKeyRef)keyByTag:(NSString *)tag error:(NSError *__autoreleasing*)error; {
     return NULL;
 }
 
-+ (void)removeKeyByTag:(NSString *)tag error:(NSError *__autoreleasing*)error; {
++ (BOOL)removeKeyByTag:(NSString *)tag error:(NSError *__autoreleasing*)error; {
     NSData *tagData = [tag dataUsingEncoding:NSUTF8StringEncoding];
     if (tagData == nil) {
-        // tell that nothing to remove.        
-        return;
+        // tell that nothing to remove.
+        if (error) {
+            *error = [JWTErrorDescription errorWithCode:JWTUnexpectedError];
+        }
+        return NO;
     }
     NSDictionary *removeAttributes = @{
             (__bridge NSString*)kSecClass: (__bridge NSString*)kSecClassKey,
             (__bridge NSString*)kSecAttrKeyType: (__bridge NSString*)kSecAttrKeyTypeRSA,
-            (__bridge NSString*)kSecAttrApplicationTag: tagData,
+            (__bridge NSString*)kSecAttrApplicationTag: tagData
     };
-    SecItemDelete((__bridge CFDictionaryRef)removeAttributes);
+    OSStatus status = SecItemDelete((__bridge CFDictionaryRef)removeAttributes);
+    if (status != errSecSuccess) {
+        if (error) {
+            *error = [NSError errorWithDomain:NSOSStatusErrorDomain code:status userInfo:nil];
+        }
+        return NO;
+    }
+    return YES;
 }
 @end
 
diff --git a/Core/Supplement/JWTErrorDescription.h b/Core/Supplement/JWTErrorDescription.h
index f46c0068..5e135e1d 100644
--- a/Core/Supplement/JWTErrorDescription.h
+++ b/Core/Supplement/JWTErrorDescription.h
@@ -26,7 +26,8 @@ typedef NS_ENUM(NSInteger, JWTError) {
     JWTBlacklistedAlgorithmError,
     JWTDecodingHeaderError,
     JWTDecodingPayloadError,
-    JWTDecodingHoldersChainEmptyError
+    JWTDecodingHoldersChainEmptyError,
+    JWTUnexpectedError
 };
 
 @interface JWTErrorDescription : NSObject
diff --git a/Core/Supplement/JWTErrorDescription.m b/Core/Supplement/JWTErrorDescription.m
index 4aad559d..2f049506 100644
--- a/Core/Supplement/JWTErrorDescription.m
+++ b/Core/Supplement/JWTErrorDescription.m
@@ -27,7 +27,8 @@ + (NSDictionary *)userDescriptionsAndCodes {
         @(JWTBlacklistedAlgorithmError): @"Algorithm in blacklist? Try to check whitelist parameter",
         @(JWTDecodingHeaderError): @"Error decoding the JWT Header segment.",
         @(JWTDecodingPayloadError): @"Error decoding the JWT Payload segment.",
-        @(JWTDecodingHoldersChainEmptyError) : @"Error decoding the JWT algorithm and data holders chain is empty!"
+        @(JWTDecodingHoldersChainEmptyError): @"Error decoding the JWT algorithm and data holders chain is empty!",
+        @(JWTUnexpectedError): @"Unexpected Error"
     });
 }
 
@@ -49,7 +50,8 @@ + (NSDictionary *)errorDescriptionsAndCodes {
         @(JWTBlacklistedAlgorithmError): @"JWTBlacklistedAlgorithmError",
         @(JWTDecodingHeaderError): @"JWTDecodingHeaderError",
         @(JWTDecodingPayloadError): @"JWTDecodingPayloadError",
-        @(JWTDecodingHoldersChainEmptyError) :@"JWTDecodingHoldersChainEmptyError"
+        @(JWTDecodingHoldersChainEmptyError): @"JWTDecodingHoldersChainEmptyError",
+        @(JWTUnexpectedError): @"JWTUnexpectedError"
     });
 }