diff --git a/src/HashSensitiveProcessor.php b/src/HashSensitiveProcessor.php
index a07d2c0..b831814 100644
--- a/src/HashSensitiveProcessor.php
+++ b/src/HashSensitiveProcessor.php
@@ -61,6 +61,11 @@ private function hash(string $value): ?string
 
         // Cut the input to the length limit specified
         $cutInput = substr($value, 0, $this->lengthLimit);
+
+        if (strlen($cutInput) === 0) {
+            return null;
+        }
+
         return hash($this->algorithm, $cutInput);
     }
 
@@ -106,7 +111,7 @@ public function traverseInputArray(array $inputArray, array $sensitiveKeys): arr
 
             // If the value is not an array or an object, hash it if it is a sensitive key
             if (is_scalar($value)) {
-                if (in_array($key, $sensitiveKeys)) {
+                if (in_array($key, $sensitiveKeys) || array_key_exists($key, $sensitiveKeys)) {
                     $inputArray[$key] = $this->hash((string) $value);
                 }
 
@@ -114,10 +119,10 @@ public function traverseInputArray(array $inputArray, array $sensitiveKeys): arr
             }
 
             // The value is either an array or an object, let traverse handle the specifics
-            if (array_key_exists($key, $sensitiveKeys)) {
+            if (in_array($key, $sensitiveKeys) || array_key_exists($key, $sensitiveKeys)) {
                 $inputArray[$key] = $this->traverse($key, $value, $sensitiveKeys[$key]);
 
-                // ExclusiveSubtree turned off means that subkeys should be checked according to ALL keys, not just
+                // ExclusiveSubtree turned off means that sub keys should be checked according to ALL keys, not just
                 // the keys in their sensitive keys subtree
                 if (!$this->exclusiveSubtree) {
                     $inputArray[$key] = $this->traverse($key, $inputArray[$key], $sensitiveKeys);
@@ -143,7 +148,7 @@ private function traverseObject(object $object, array $sensitiveKeys): object
         foreach (get_object_vars($object) as $key => $value) {
             // If the value is not an array or an object, hash it if it is a sensitive key
             if (is_scalar($value)) {
-                if (array_key_exists($key, $sensitiveKeys)) {
+                if (in_array($key, $sensitiveKeys) || array_key_exists($key, $sensitiveKeys)) {
                     $object->{$key} = $this->hash((string) $value);
                 }
 
@@ -151,11 +156,11 @@ private function traverseObject(object $object, array $sensitiveKeys): object
             }
 
             // The value is either an array or an object, let traverse handle the specifics
-            if (array_key_exists($key, $sensitiveKeys)) {
+            if (in_array($key, $sensitiveKeys) || array_key_exists($key, $sensitiveKeys)) {
                 $object->{$key} = $this->traverse($key, $value, $sensitiveKeys[$key]);
 
                 if (!$this->exclusiveSubtree) {
-                    $object->{$key} = $this->traverse($key, $object->{key}, $sensitiveKeys);
+                    $object->{$key} = $this->traverse($key, $object->{$key}, $sensitiveKeys);
                 }
             } else {
                 $object->{$key} = $this->traverse($key, $value, $sensitiveKeys);
diff --git a/tests/HashSensitiveTest.php b/tests/HashSensitiveTest.php
index 2b39ca9..bc69528 100644
--- a/tests/HashSensitiveTest.php
+++ b/tests/HashSensitiveTest.php
@@ -5,137 +5,130 @@
 namespace HashSensitiveTests;
 
 use HashSensitive\HashSensitiveProcessor;
+use TypeError;
 
-//it('redacts records contexts', function (): void {
-//    $sensitive_keys = ['test' => 3];
-//    $processor = new HashSensitiveProcessor($sensitive_keys);
-//
-//    $record = $this->getRecord(context: ['test' => 'foobar']);
-//    expect($processor($record)->context)->toBe(['test' => 'foo***']);
-//});
-//
-//it('redacts using template', function (): void {
-//    $sensitive_keys = ['test' => 2];
-//    $processor = new HashSensitiveProcessor($sensitive_keys, template: '%s(redacted)');
-//
-//    $record = $this->getRecord(context: ['test' => 'foobar']);
-//    expect($processor($record)->context)->toBe(['test' => 'fo****(redacted)']);
-//});
-//
-//it('redacts discarding masked', function (): void {
-//    $sensitive_keys = ['test' => 1];
-//    $processor = new HashSensitiveProcessor($sensitive_keys, template: '...');
-//
-//    $record = $this->getRecord(context: ['test' => 'foobar123']);
-//    expect($processor($record)->context)->toBe(['test' => 'f...']);
-//});
-//
-//it('truncates masked characters', function (): void {
-//    $sensitive_keys = ['test' => 3];
-//    $processor = new HashSensitiveProcessor($sensitive_keys, lengthLimit: 5);
-//
-//    $record = $this->getRecord(context: ['test' => 'foobar']);
-//    expect($processor($record)->context)->toBe(['test' => 'foo**']);
-//});
-//
-//it('truncates visible characters', function (): void {
-//    $sensitive_keys = ['test' => 3];
-//    $processor = new HashSensitiveProcessor($sensitive_keys, lengthLimit: 2);
-//
-//    $record = $this->getRecord(context: ['test' => 'foobar']);
-//    expect($processor($record)->context)->toBe(['test' => 'fo']);
-//});
-//
-//it('overrides default replacement', function (): void {
-//    $sensitive_keys = ['test' => 3];
-//    $processor = new HashSensitiveProcessor($sensitive_keys, '_');
-//
-//    $record = $this->getRecord(context: ['test' => 'foobar']);
-//    expect($processor($record)->context)->toBe(['test' => 'foo___']);
-//});
-//
-//it('redacts from right to left', function (): void {
-//    $sensitive_keys = ['test' => -3];
-//    $processor = new HashSensitiveProcessor($sensitive_keys);
-//
-//    $record = $this->getRecord(context: ['test' => 'foobar']);
-//    expect($processor($record)->context)->toBe(['test' => '***bar']);
-//});
-//
-//it('truncates masked from right to left', function (): void {
-//    $sensitive_keys = ['test' => -3];
-//    $processor = new HashSensitiveProcessor($sensitive_keys, lengthLimit: 4);
-//
-//    $record = $this->getRecord(context: ['test' => 'foobar']);
-//    expect($processor($record)->context)->toBe(['test' => '*bar']);
-//});
-//
-//it('truncates visible from right to left', function (): void {
-//    $sensitive_keys = ['test' => -3];
-//    $processor = new HashSensitiveProcessor($sensitive_keys, lengthLimit: 2);
-//
-//    $record = $this->getRecord(context: ['test' => 'foobar']);
-//    expect($processor($record)->context)->toBe(['test' => 'ar']);
-//});
-//
-//it('redacts nested arrays', function (): void {
-//    $sensitive_keys = ['test' => ['nested' => 3]];
-//    $processor = new HashSensitiveProcessor($sensitive_keys);
-//
-//    $record = $this->getRecord(context: ['test' => ['nested' => 'foobar']]);
-//    expect($processor($record)->context)->toBe(['test' => ['nested' => 'foo***']]);
-//});
-//
-//it('redacts inside nested arrays', function (): void {
-//    $sensitive_keys = ['nested' => 3];
-//    $processor = new HashSensitiveProcessor($sensitive_keys);
-//
-//    $record = $this->getRecord(context: ['test' => ['nested' => 'foobar']]);
-//    expect($processor($record)->context)->toBe(['test' => ['nested' => 'foo***']]);
-//});
-//
-//it('redacts nested objects', function (): void {
-//    $nested = new \stdClass();
-//    $nested->value = 'foobar';
-//    $nested->nested = ['value' => 'bazqux'];
-//
-//    $sensitive_keys = ['test' => ['nested' => ['value' => 3, 'nested' => ['value' => -3]]]];
-//    $processor = new HashSensitiveProcessor($sensitive_keys);
-//
-//    $record = $this->getRecord(context: ['test' => ['nested' => $nested]]);
-//
-//    expect($processor($record)->context)->toBe(['test' => ['nested' => $nested]]);
-//    expect($nested->value)->toBe('foo***');
-//    expect($nested->nested['value'])->toBe('***qux');
-//});
-//
-//it('redacts inside nested objects', function (): void {
-//    $nested = new \stdClass();
-//    $nested->value = 'foobar';
-//    $nested->nested = ['value' => 'bazqux'];
-//
-//    $sensitive_keys = ['nested' => ['value' => -3]];
-//    $processor = new HashSensitiveProcessor($sensitive_keys);
-//
-//    $record = $this->getRecord(context: ['test' => ['nested' => $nested]]);
-//
-//    expect($processor($record)->context)->toBe(['test' => ['nested' => $nested]]);
-//    expect($nested->value)->toBe('***bar');
-//    expect($nested->nested['value'])->toBe('***qux');
-//});
-//
-//it('preserves empty values', function (): void {
-//    $sensitive_keys = ['test' => 3, 'optionalKey' => 10];
-//    $processor = new HashSensitiveProcessor($sensitive_keys);
-//
-//    $record = $this->getRecord(context: ['test' => 'foobar', 'optionalKey' => '']);
-//    expect($processor($record)->context)->toBe(['test' => 'foo***', 'optionalKey' => '']);
-//});
-//
-//it('throws when finds an un-traversable value', function (): void {
-//    $sensitive_keys = ['test' => 3];
-//    $processor = new HashSensitiveProcessor($sensitive_keys);
-//
-//    $record = $this->getRecord(context: ['test' => fopen(__FILE__, 'rb')]);
-//    $processor($record);
-//})->throws(\UnexpectedValueException::class, 'Don\'t know how to traverse value at key test');
+it('redacts records contexts', function (): void {
+    $sensitive_keys = ['test'];
+    $processor = new HashSensitiveProcessor($sensitive_keys);
+
+    $record = $this->getRecord(context: ['test' => 'foobar']);
+    expect($processor($record)->context)->toBe(['test' => 'c3ab8ff13720e8ad9047dd39466b3c8974e592c2fa383d4a3960714caef0c4f2']);
+});
+
+it('truncates masked characters', function (): void {
+    $sensitive_keys = ['test'];
+    $processor = new HashSensitiveProcessor($sensitive_keys, lengthLimit: 5);
+
+    $record = $this->getRecord(context: ['test' => 'foobar']);
+    // Only `fooba` should be hashed, the first 5 characters of `foobar`
+    expect($processor($record)->context)->toBe(['test' => '41cbe1a87981490351ccad5346d96da0ac10678670b31fc0ab209aed1b5bc515']);
+});
+
+it('doesn\'t truncate more than the string length', function (): void {
+    $sensitive_keys = ['test'];
+    $processor = new HashSensitiveProcessor($sensitive_keys, lengthLimit: 10);
+
+    $record = $this->getRecord(context: ['test' => 'foobar']);
+    expect($processor($record)->context)->toBe(['test' => 'c3ab8ff13720e8ad9047dd39466b3c8974e592c2fa383d4a3960714caef0c4f2']);
+});
+
+it('doesn\'t truncate when length limit is 0', function (): void {
+    $sensitive_keys = ['test'];
+    $processor = new HashSensitiveProcessor($sensitive_keys, lengthLimit: 0);
+
+    $record = $this->getRecord(context: ['test' => 'foobar']);
+    expect($processor($record)->context)->toBe(['test' => null]);
+});
+
+it('doesn\'t truncate when length limit is not set', function (): void {
+    $sensitive_keys = ['test'];
+    $processor = new HashSensitiveProcessor($sensitive_keys);
+
+    $record = $this->getRecord(context: ['test' => 'foobar']);
+    expect($processor($record)->context)->toBe(['test' => 'c3ab8ff13720e8ad9047dd39466b3c8974e592c2fa383d4a3960714caef0c4f2']);
+});
+
+
+it('redacts nested arrays', function (): void {
+    $sensitive_keys = ['test' => ['nested']];
+    $processor = new HashSensitiveProcessor($sensitive_keys);
+
+    $record = $this->getRecord(context: ['test' => ['nested' => 'foobar']]);
+    expect($processor($record)->context)->toBe(['test' => ['nested' => 'c3ab8ff13720e8ad9047dd39466b3c8974e592c2fa383d4a3960714caef0c4f2']]);
+});
+
+it('keeps non redacted nested arrays intact', function (): void {
+    $sensitive_keys = ['test' => ['nested']];
+    $processor = new HashSensitiveProcessor($sensitive_keys);
+
+    $record = $this->getRecord(context: ['test' => ['nested' => 'foobar', 'no_hash' => 'foobar']]);
+    expect($processor($record)->context)->toBe(['test' => ['nested' => 'c3ab8ff13720e8ad9047dd39466b3c8974e592c2fa383d4a3960714caef0c4f2', 'no_hash' => 'foobar']]);
+});
+
+it('redacts inside nested arrays', function (): void {
+    $sensitive_keys = ['nested'];
+    $processor = new HashSensitiveProcessor($sensitive_keys);
+
+    $record = $this->getRecord(context: ['test' => ['nested' => 'foobar']]);
+    expect($processor($record)->context)->toBe(['test' => ['nested' => 'c3ab8ff13720e8ad9047dd39466b3c8974e592c2fa383d4a3960714caef0c4f2']]);
+});
+
+it('redacts nested objects', function (): void {
+    $nested = new \stdClass();
+    $nested->value = 'foobar';
+    $nested->nested = ['value' => 'bazqux'];
+
+    $sensitive_keys = ['test' => ['nested' => ['value', 'nested' => ['value']]]];
+    $processor = new HashSensitiveProcessor($sensitive_keys);
+
+    $record = $this->getRecord(context: ['test' => ['nested' => $nested]]);
+
+    expect($processor($record)->context)->toBe(['test' => ['nested' => $nested]])
+        ->and($nested->value)->toBe('c3ab8ff13720e8ad9047dd39466b3c8974e592c2fa383d4a3960714caef0c4f2')
+        ->and($nested->nested['value'])->toBe('972c5e1203896784a7cf9dd60acd443a1065e19ad5f92e59a9180c185f065c04');
+});
+
+it('keeps non redacted nested objects intact', function (): void {
+    $nested = new \stdClass();
+    $nested->value = 'foobar';
+    $nested->nested = ['value' => 'bazqux', 'no_hash' => 'foobar'];
+
+    $sensitive_keys = ['test' => ['nested' => ['value', 'nested' => ['value']]]];
+    $processor = new HashSensitiveProcessor($sensitive_keys);
+
+    $record = $this->getRecord(context: ['test' => ['nested' => $nested]]);
+
+    expect($processor($record)->context)->toBe(['test' => ['nested' => $nested]])
+        ->and($nested->nested['no_hash'])->toBe('foobar');
+});
+
+it('redacts inside nested objects', function (): void {
+    $nested = new \stdClass();
+    $nested->value = 'foobar';
+    $nested->nested = ['value' => 'bazqux'];
+
+    $sensitive_keys = ['nested' => ['value']];
+    $processor = new HashSensitiveProcessor($sensitive_keys);
+
+    $record = $this->getRecord(context: ['test' => ['nested' => $nested]]);
+
+    expect($processor($record)->context)->toBe(['test' => ['nested' => $nested]])
+        ->and($nested->value)->toBe('c3ab8ff13720e8ad9047dd39466b3c8974e592c2fa383d4a3960714caef0c4f2')
+        ->and($nested->nested['value'])->toBe('972c5e1203896784a7cf9dd60acd443a1065e19ad5f92e59a9180c185f065c04');
+});
+
+it('preserves empty values', function (): void {
+    $sensitive_keys = ['test', 'optionalKey'];
+    $processor = new HashSensitiveProcessor($sensitive_keys);
+
+    $record = $this->getRecord(context: ['test' => 'foobar', 'optionalKey' => '']);
+    expect($processor($record)->context)->toBe(['test' => 'c3ab8ff13720e8ad9047dd39466b3c8974e592c2fa383d4a3960714caef0c4f2', 'optionalKey' => null]);
+});
+
+it('throws when finds an un-traversable value', function (): void {
+    $sensitive_keys = ['test'];
+    $processor = new HashSensitiveProcessor($sensitive_keys);
+
+    $record = $this->getRecord(context: ['test' => fopen(__FILE__, 'rb')]);
+    $processor($record);
+})->throws(TypeError::class, 'Argument #2 ($value) must be of type object|array, resource given');