diff --git a/SafeExamBrowser.Browser/Handlers/ResourceHandler.cs b/SafeExamBrowser.Browser/Handlers/ResourceHandler.cs
index 477810d5..bafa5a09 100644
--- a/SafeExamBrowser.Browser/Handlers/ResourceHandler.cs
+++ b/SafeExamBrowser.Browser/Handlers/ResourceHandler.cs
@@ -107,7 +107,7 @@ namespace SafeExamBrowser.Browser.Handlers
 			var headers = new NameValueCollection(request.Headers);
 			var urlWithoutFragment = request.Url.Split('#')[0];
 			var hash = algorithm.ComputeHash(Encoding.UTF8.GetBytes(urlWithoutFragment + settings.HashValue));
-			var configurationKey = BitConverter.ToString(hash).Replace("-", string.Empty);
+			var configurationKey = BitConverter.ToString(hash).ToLower().Replace("-", string.Empty);
 
 			// TODO: Implement Browser Exam Key calculation.
 			// headers["X-SafeExamBrowser-RequestHash"] = ...;
diff --git a/SafeExamBrowser.Configuration.UnitTests/ConfigurationData/DataProcessorTests.cs b/SafeExamBrowser.Configuration.UnitTests/ConfigurationData/DataProcessorTests.cs
new file mode 100644
index 00000000..e06ca6ae
--- /dev/null
+++ b/SafeExamBrowser.Configuration.UnitTests/ConfigurationData/DataProcessorTests.cs
@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2020 ETH Zürich, Educational Development and Technology (LET)
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+using System.Collections.Generic;
+using System.Reflection;
+using System.Runtime.Serialization.Formatters.Binary;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using SafeExamBrowser.Configuration.ConfigurationData;
+using SafeExamBrowser.Settings;
+
+namespace SafeExamBrowser.Configuration.UnitTests.ConfigurationData
+{
+	[TestClass]
+	public class DataProcessorTests
+	{
+		private DataProcessor sut;
+
+		[TestInitialize]
+		public void Initialize()
+		{
+			sut = new DataProcessor();
+		}
+
+		[TestMethod]
+		public void MustCalculateCorrectHashValue()
+		{
+			var formatter = new BinaryFormatter();
+			var path1 = $"{nameof(SafeExamBrowser)}.{nameof(Configuration)}.{nameof(UnitTests)}.{nameof(ConfigurationData)}.TestDictionary1.bin";
+			var path2 = $"{nameof(SafeExamBrowser)}.{nameof(Configuration)}.{nameof(UnitTests)}.{nameof(ConfigurationData)}.TestDictionary2.bin";
+			var path3 = $"{nameof(SafeExamBrowser)}.{nameof(Configuration)}.{nameof(UnitTests)}.{nameof(ConfigurationData)}.TestDictionary3.bin";
+			var stream1 = Assembly.GetAssembly(GetType()).GetManifestResourceStream(path1);
+			var stream2 = Assembly.GetAssembly(GetType()).GetManifestResourceStream(path2);
+			var stream3 = Assembly.GetAssembly(GetType()).GetManifestResourceStream(path3);
+			var data1 = formatter.Deserialize(stream1) as IDictionary<string, object>;
+			var data2 = formatter.Deserialize(stream2) as IDictionary<string, object>;
+			var data3 = formatter.Deserialize(stream3) as IDictionary<string, object>;
+			var settings1 = new AppSettings();
+			var settings2 = new AppSettings();
+			var settings3 = new AppSettings();
+
+			sut.Process(data1, settings1);
+			sut.Process(data2, settings2);
+			sut.Process(data3, settings3);
+
+			Assert.AreEqual("6063c3351ed1ac878c05072598d5079e30ca763c957d8e04bd45131c08f88d1a", settings1.Browser.HashValue);
+			Assert.AreEqual("4fc002d2ae4faf994a14bede54d95ac58a1a2cb9b59bc5b4277ff29559b46e3d", settings2.Browser.HashValue);
+			Assert.AreEqual("ab426e25b795c917f1fb40f7ef8e5757ef97d7c7ad6792e655c4421d47329d7a", settings3.Browser.HashValue);
+		}
+	}
+}
diff --git a/SafeExamBrowser.Configuration.UnitTests/ConfigurationData/TestDictionary1.bin b/SafeExamBrowser.Configuration.UnitTests/ConfigurationData/TestDictionary1.bin
new file mode 100644
index 00000000..a95d7e5a
Binary files /dev/null and b/SafeExamBrowser.Configuration.UnitTests/ConfigurationData/TestDictionary1.bin differ
diff --git a/SafeExamBrowser.Configuration.UnitTests/ConfigurationData/TestDictionary2.bin b/SafeExamBrowser.Configuration.UnitTests/ConfigurationData/TestDictionary2.bin
new file mode 100644
index 00000000..5c4d3a23
Binary files /dev/null and b/SafeExamBrowser.Configuration.UnitTests/ConfigurationData/TestDictionary2.bin differ
diff --git a/SafeExamBrowser.Configuration.UnitTests/ConfigurationData/TestDictionary3.bin b/SafeExamBrowser.Configuration.UnitTests/ConfigurationData/TestDictionary3.bin
new file mode 100644
index 00000000..d65333fb
Binary files /dev/null and b/SafeExamBrowser.Configuration.UnitTests/ConfigurationData/TestDictionary3.bin differ
diff --git a/SafeExamBrowser.Configuration.UnitTests/SafeExamBrowser.Configuration.UnitTests.csproj b/SafeExamBrowser.Configuration.UnitTests/SafeExamBrowser.Configuration.UnitTests.csproj
index 72b9a974..ad3a996a 100644
--- a/SafeExamBrowser.Configuration.UnitTests/SafeExamBrowser.Configuration.UnitTests.csproj
+++ b/SafeExamBrowser.Configuration.UnitTests/SafeExamBrowser.Configuration.UnitTests.csproj
@@ -87,6 +87,7 @@
     <Reference Include="System.Xml.Linq" />
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="ConfigurationData\DataProcessorTests.cs" />
     <Compile Include="ConfigurationRepositoryTests.cs" />
     <Compile Include="Cryptography\HashAlgorithmTests.cs" />
     <Compile Include="Cryptography\PasswordEncryptionTests.cs" />
@@ -106,6 +107,9 @@
     </None>
     <EmbeddedResource Include="DataFormats\XmlTestSettings.xml" />
     <EmbeddedResource Include="UnitTestCert.pfx" />
+    <EmbeddedResource Include="ConfigurationData\TestDictionary1.bin" />
+    <EmbeddedResource Include="ConfigurationData\TestDictionary2.bin" />
+    <EmbeddedResource Include="ConfigurationData\TestDictionary3.bin" />
     <None Include="packages.config">
       <SubType>Designer</SubType>
     </None>
diff --git a/SafeExamBrowser.Configuration/ConfigurationData/DataProcessor.cs b/SafeExamBrowser.Configuration/ConfigurationData/DataProcessor.cs
index b76c3b2d..1a4c0a6d 100644
--- a/SafeExamBrowser.Configuration/ConfigurationData/DataProcessor.cs
+++ b/SafeExamBrowser.Configuration/ConfigurationData/DataProcessor.cs
@@ -12,7 +12,6 @@ using System.Globalization;
 using System.IO;
 using System.Linq;
 using System.Security.Cryptography;
-using System.Text;
 using SafeExamBrowser.Settings;
 
 namespace SafeExamBrowser.Configuration.ConfigurationData
@@ -28,22 +27,23 @@ namespace SafeExamBrowser.Configuration.ConfigurationData
 		{
 			using (var algorithm = new SHA256Managed())
 			using (var stream = new MemoryStream())
-			using (var writer = new StreamWriter(stream, Encoding.UTF8))
+			using (var writer = new StreamWriter(stream))
 			{
 				Serialize(rawData, writer);
+
 				writer.Flush();
 				stream.Seek(0, SeekOrigin.Begin);
 
-				var hash = algorithm.ComputeHash(stream);
-				var hashString = BitConverter.ToString(hash).Replace("-", string.Empty);
+				var hashBytes = algorithm.ComputeHash(stream);
+				var hashValue = BitConverter.ToString(hashBytes).ToLower().Replace("-", string.Empty);
 
-				settings.Browser.HashValue = hashString;
+				settings.Browser.HashValue = hashValue;
 			}
 		}
 
 		private void Serialize(IDictionary<string, object> dictionary, StreamWriter stream)
 		{
-			var orderedByKey = dictionary.OrderBy(d => d.Key, StringComparer.OrdinalIgnoreCase).ToList();
+			var orderedByKey = dictionary.OrderBy(d => d.Key, StringComparer.InvariantCulture).ToList();
 
 			stream.Write('{');