diff --git a/gradle.properties b/gradle.properties
index a14b8c2..424ade3 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -1,3 +1,3 @@
-jwo.version = 2024.02.02
+jwo.version = 2024.02.09
 lys.version = 2024.02.01
 guice.version = 5.0.1
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 1af9e09..a80b22c 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,6 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.5-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.6-bin.zip
 networkTimeout=10000
 validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME
diff --git a/src/main/java/net/woggioni/jwo/Hash.java b/src/main/java/net/woggioni/jwo/Hash.java
index 57329ad..0e48cb0 100644
--- a/src/main/java/net/woggioni/jwo/Hash.java
+++ b/src/main/java/net/woggioni/jwo/Hash.java
@@ -5,12 +5,15 @@ import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 import lombok.SneakyThrows;
 
+import java.io.ByteArrayOutputStream;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.security.DigestInputStream;
 import java.security.DigestOutputStream;
 import java.security.MessageDigest;
 
+import static net.woggioni.jwo.JWO.newThrowable;
+
 @EqualsAndHashCode
 @RequiredArgsConstructor
 public class Hash {
@@ -87,6 +90,33 @@ public class Hash {
         return new String(hexChars);
     }
 
+    public static byte[] hexToBytes(String hexString) {
+        ByteArrayOutputStream baos = new ByteArrayOutputStream();
+        if (hexString.length() % 2 != 0) {
+            throw newThrowable(IllegalArgumentException.class, "Hex string length must be even," +
+                " string has length '%d' instead", hexString.length());
+        }
+        int lim = hexString.length() / 2;
+        for(int i = 0; i < lim; i++) {
+            int tmp = 0;
+            for (int j = 0; j < 2; j++) {
+                int c = hexString.charAt(i * 2 + j);
+                if (c >= '0' && c <= '9') {
+                    c -= '0';
+                } else if (c >= 'A' && c <= 'F') {
+                    c -= 'A' - 10;
+                } else if(c >= 'a' && c <= 'f') {
+                    c -= 'a' - 10;
+                } else {
+                    throw newThrowable(IllegalArgumentException.class, "Illegal hex char '%c'", c);
+                }
+                tmp |= (c << 4 * (1 - j));
+            }
+            baos.write(tmp);
+        }
+        return baos.toByteArray();
+    }
+
     @Override
     public String toString() {
         return bytesToHex(bytes);
diff --git a/src/main/java/net/woggioni/jwo/JWO.java b/src/main/java/net/woggioni/jwo/JWO.java
index aebd449..d427394 100644
--- a/src/main/java/net/woggioni/jwo/JWO.java
+++ b/src/main/java/net/woggioni/jwo/JWO.java
@@ -233,16 +233,8 @@ public class JWO {
         }
     }
 
-    final private static char[] hexArray = "0123456789ABCDEF".toCharArray();
-
     public static String bytesToHex(byte[] bytes) {
-        char[] hexChars = new char[bytes.length * 2];
-        for (int j = 0; j < bytes.length; j++) {
-            int v = bytes[j] & 0xFF;
-            hexChars[j * 2] = hexArray[v >>> 4];
-            hexChars[j * 2 + 1] = hexArray[v & 0x0F];
-        }
-        return new String(hexChars);
+        return Hash.bytesToHex(bytes);
     }
 
     @SneakyThrows
diff --git a/src/test/java/net/woggioni/jwo/HashTest.java b/src/test/java/net/woggioni/jwo/HashTest.java
index dcacb46..f0fd53b 100644
--- a/src/test/java/net/woggioni/jwo/HashTest.java
+++ b/src/test/java/net/woggioni/jwo/HashTest.java
@@ -3,9 +3,15 @@ package net.woggioni.jwo;
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtensionContext;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.ArgumentsProvider;
+import org.junit.jupiter.params.provider.ArgumentsSource;
 
 import java.io.ByteArrayInputStream;
 import java.util.Random;
+import java.util.stream.Stream;
 
 public class HashTest {
 
@@ -42,4 +48,34 @@ public class HashTest {
         Assertions.assertNotEquals(hash1, hash2);
         Assertions.assertNotEquals(hash1.toString(), hash2.toString());
     }
+
+
+    private static class HexTestArguments implements ArgumentsProvider {
+        @Override
+        public Stream<? extends Arguments> provideArguments(
+            ExtensionContext extensionContext
+        ) {
+            return Stream.of(
+                Arguments.of("A41D767EEF6084823F250E954BDD48CF", null),
+                Arguments.of("A41D767eeF6084823f250E954bdD48CF", null),
+                Arguments.of("A41D767EEF6084823F250E954BDD48C", IllegalArgumentException.class),
+                Arguments.of("A41D767xEF6084823F250E954BDD48C", IllegalArgumentException.class),
+                Arguments.of("A41D767ZeF6084823f250E954bdD48C", IllegalArgumentException.class),
+                Arguments.of("A41D767eeF6084823f250E954bdD4x", IllegalArgumentException.class)
+            );
+        }
+    }
+    @ArgumentsSource(HexTestArguments.class)
+    @ParameterizedTest
+    public void hexTest(String sourceString, Class<? extends Throwable> t) {
+        if(t != null) {
+            Assertions.assertThrows(t, () ->
+                Hash.hexToBytes(sourceString)
+            );
+        } else {
+            byte[] bytes = Hash.hexToBytes(sourceString);
+            Assertions.assertEquals(sourceString.length() / 2, bytes.length);
+            Assertions.assertEquals(sourceString.toUpperCase(), Hash.bytesToHex(bytes));
+        }
+    }
 }