diff --git a/authorization-dotnet/HowToSecurePasswordsWithBCryptNET/HowToSecurePasswordsWithBCryptNET/HowToSecurePasswordsWithBCryptNET.csproj b/authorization-dotnet/HowToSecurePasswordsWithBCryptNET/HowToSecurePasswordsWithBCryptNET/HowToSecurePasswordsWithBCryptNET.csproj
index 6939f4cac9..eb7f91f71b 100644
--- a/authorization-dotnet/HowToSecurePasswordsWithBCryptNET/HowToSecurePasswordsWithBCryptNET/HowToSecurePasswordsWithBCryptNET.csproj
+++ b/authorization-dotnet/HowToSecurePasswordsWithBCryptNET/HowToSecurePasswordsWithBCryptNET/HowToSecurePasswordsWithBCryptNET.csproj
@@ -2,13 +2,13 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net10.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="BCrypt.Net-Next" Version="4.0.3" />
+    <PackageReference Include="BCrypt.Net-Next" Version="4.2.0" />
   </ItemGroup>
 
 </Project>
diff --git a/authorization-dotnet/HowToSecurePasswordsWithBCryptNET/HowToSecurePasswordsWithBCryptNET/PasswordLoginService.cs b/authorization-dotnet/HowToSecurePasswordsWithBCryptNET/HowToSecurePasswordsWithBCryptNET/PasswordLoginService.cs
new file mode 100644
index 0000000000..a9090653dc
--- /dev/null
+++ b/authorization-dotnet/HowToSecurePasswordsWithBCryptNET/HowToSecurePasswordsWithBCryptNET/PasswordLoginService.cs
@@ -0,0 +1,16 @@
+namespace HowToSecurePasswordsWithBCryptNET;
+
+public class PasswordLoginService
+{
+    public const int CurrentWorkFactor = 11;
+
+    public string? LoginAndUpgrade(string password, string storedHash)
+    {
+        if (!BCrypt.Net.BCrypt.Verify(password, storedHash))
+            return null;
+
+        return BCrypt.Net.BCrypt.PasswordNeedsRehash(storedHash, CurrentWorkFactor)
+            ? BCrypt.Net.BCrypt.HashPassword(password, CurrentWorkFactor)
+            : null;
+    }
+}
diff --git a/authorization-dotnet/HowToSecurePasswordsWithBCryptNET/HowToSecurePasswordsWithBCryptNET/Program.cs b/authorization-dotnet/HowToSecurePasswordsWithBCryptNET/HowToSecurePasswordsWithBCryptNET/Program.cs
index 49f0e1b539..813adbf4c3 100644
--- a/authorization-dotnet/HowToSecurePasswordsWithBCryptNET/HowToSecurePasswordsWithBCryptNET/Program.cs
+++ b/authorization-dotnet/HowToSecurePasswordsWithBCryptNET/HowToSecurePasswordsWithBCryptNET/Program.cs
@@ -1,2 +1,9 @@
-// See https://aka.ms/new-console-template for more information
-Console.WriteLine("Please, check test project for examples.");
+using HowToSecurePasswordsWithBCryptNET;
+
+var passwordHash = BCrypt.Net.BCrypt.HashPassword("Password123!");
+Console.WriteLine($"Hash: {passwordHash}");
+Console.WriteLine($"Verified: {BCrypt.Net.BCrypt.Verify("Password123!", passwordHash)}");
+
+var oldHash = BCrypt.Net.BCrypt.HashPassword("Password123!", workFactor: 6);
+var upgradedHash = new PasswordLoginService().LoginAndUpgrade("Password123!", oldHash);
+Console.WriteLine($"Upgraded hash: {upgradedHash}");
diff --git a/authorization-dotnet/HowToSecurePasswordsWithBCryptNET/Test/BCryptTests.cs b/authorization-dotnet/HowToSecurePasswordsWithBCryptNET/Test/BCryptTests.cs
index 6e3f0affc6..7ab1bf4a28 100644
--- a/authorization-dotnet/HowToSecurePasswordsWithBCryptNET/Test/BCryptTests.cs
+++ b/authorization-dotnet/HowToSecurePasswordsWithBCryptNET/Test/BCryptTests.cs
@@ -1,6 +1,7 @@
 namespace Test;
 
 using BCrypt.Net;
+using HowToSecurePasswordsWithBCryptNET;
 
 public class BCryptTests
 {
@@ -57,4 +58,153 @@ public void WhenHashingPasswordWithHigherWorkFactor_ThenReturnsNotNullString()
 
         Assert.NotNull(passwordHash);
     }
-}
\ No newline at end of file
+
+    [Fact]
+    public void WhenWorkFactorBelowMinimum_ThenPasswordNeedsRehashReturnsTrue()
+    {
+        var passwordHash = BCrypt.HashPassword("Password123!", workFactor: 6);
+
+        var result = BCrypt.PasswordNeedsRehash(passwordHash, 11);
+
+        Assert.True(result);
+    }
+
+    [Fact]
+    public void WhenWorkFactorAtMinimum_ThenPasswordNeedsRehashReturnsFalse()
+    {
+        var passwordHash = BCrypt.HashPassword("Password123!", workFactor: 11);
+
+        var result = BCrypt.PasswordNeedsRehash(passwordHash, 11);
+
+        Assert.False(result);
+    }
+
+    [Fact]
+    public void WhenInterrogatingHash_ThenReturnsVersionAndWorkFactor()
+    {
+        var passwordHash = BCrypt.HashPassword("Password123!");
+
+        var info = BCrypt.InterrogateHash(passwordHash);
+
+        Assert.Equal("2a", info.Version);
+        Assert.Equal("11", info.WorkFactor);
+        Assert.Equal("$2a$11", info.Settings);
+        Assert.Equal(60, passwordHash.Length);
+    }
+
+    [Fact]
+    public void WhenVerifyingPhpGenerated2yHash_ThenVerificationSucceeds()
+    {
+        // The password_verify() example from the PHP manual.
+        const string phpHash = "$2y$10$.vGA1O9wmRjrwAVXD98HNOgsNpDczlqm3Jq7KnEd1rVAGv3Fykk1a";
+
+        Assert.True(BCrypt.Verify("rasmuslerdorf", phpHash));
+        Assert.False(BCrypt.Verify("Wr0ngPassword!", phpHash));
+    }
+
+    [Theory]
+    [InlineData('a')]
+    [InlineData('b')]
+    [InlineData('x')]
+    [InlineData('y')]
+    public void WhenUsingSupportedRevision_ThenHashVerifies(char revision)
+    {
+        var salt = BCrypt.GenerateSalt(6, revision);
+        var passwordHash = BCrypt.HashPassword("Password123!", salt);
+
+        Assert.StartsWith($"$2{revision}$", passwordHash);
+        Assert.True(BCrypt.Verify("Password123!", passwordHash));
+    }
+
+    [Fact]
+    public void WhenVerifyingUnsupportedRevision_ThenThrowsSaltParseException()
+    {
+        const string hash = "$2c$10$.vGA1O9wmRjrwAVXD98HNOgsNpDczlqm3Jq7KnEd1rVAGv3Fykk1a";
+
+        Assert.Throws<SaltParseException>(() => BCrypt.Verify("rasmuslerdorf", hash));
+    }
+
+    [Fact]
+    public void WhenVerifyingEnhancedHashWithPlainVerify_ThenVerificationFails()
+    {
+        var passwordHash = BCrypt.EnhancedHashPassword("Password123!");
+
+        Assert.StartsWith("$2a$11$", passwordHash);
+        Assert.False(BCrypt.Verify("Password123!", passwordHash));
+        Assert.True(BCrypt.EnhancedVerify("Password123!", passwordHash));
+        Assert.False(BCrypt.EnhancedVerify("Password123!", passwordHash, HashType.SHA512));
+    }
+
+    [Fact]
+    public void WhenPasswordsShareFirst72Bytes_ThenEitherVerifiesAgainstEitherHash()
+    {
+        var prefix = new string('p', 72);
+        var firstPassword = prefix + "ONE";
+        var secondPassword = prefix + "TWO";
+
+        var firstHash = BCrypt.HashPassword(firstPassword, workFactor: 6);
+        var secondHash = BCrypt.HashPassword(secondPassword, workFactor: 6);
+
+        Assert.True(BCrypt.Verify(secondPassword, firstHash));
+        Assert.True(BCrypt.Verify(firstPassword, secondHash));
+    }
+
+    [Fact]
+    public void WhenPasswordsShareFirst72Bytes_ThenEnhancedVerifyTellsThemApart()
+    {
+        var prefix = new string('p', 72);
+        var firstHash = BCrypt.EnhancedHashPassword(prefix + "ONE", workFactor: 6);
+
+        Assert.False(BCrypt.EnhancedVerify(prefix + "TWO", firstHash));
+    }
+
+    [Theory]
+    [InlineData(3)]
+    [InlineData(32)]
+    public void WhenWorkFactorOutOfRange_ThenThrowsArgumentOutOfRangeException(int workFactor)
+    {
+        var exception = Assert.Throws<ArgumentOutOfRangeException>(
+            () => BCrypt.HashPassword("Password123!", workFactor));
+
+        Assert.Equal("workFactor", exception.ParamName);
+    }
+
+    [Fact]
+    public void WhenWorkFactorAtBounds_ThenSaltIsGenerated()
+    {
+        // Never hash at work factor 31: that is 2^31 rounds. The salt alone proves the bound.
+        Assert.StartsWith("$2a$04$", BCrypt.GenerateSalt(4));
+        Assert.StartsWith("$2a$31$", BCrypt.GenerateSalt(31));
+    }
+
+    [Fact]
+    public void WhenStoredHashIsUnderCost_ThenLoginReturnsUpgradedHash()
+    {
+        var service = new PasswordLoginService();
+        var storedHash = BCrypt.HashPassword("Password123!", workFactor: 6);
+
+        var newHash = service.LoginAndUpgrade("Password123!", storedHash);
+
+        Assert.NotNull(newHash);
+        Assert.StartsWith("$2a$11$", newHash);
+        Assert.True(BCrypt.Verify("Password123!", newHash));
+    }
+
+    [Fact]
+    public void WhenStoredHashIsCurrent_ThenLoginReturnsNull()
+    {
+        var service = new PasswordLoginService();
+        var storedHash = BCrypt.HashPassword("Password123!", workFactor: 11);
+
+        Assert.Null(service.LoginAndUpgrade("Password123!", storedHash));
+    }
+
+    [Fact]
+    public void WhenPasswordIsWrong_ThenLoginReturnsNull()
+    {
+        var service = new PasswordLoginService();
+        var storedHash = BCrypt.HashPassword("Password123!", workFactor: 6);
+
+        Assert.Null(service.LoginAndUpgrade("Wr0ngPassword!", storedHash));
+    }
+}
diff --git a/authorization-dotnet/HowToSecurePasswordsWithBCryptNET/Test/Test.csproj b/authorization-dotnet/HowToSecurePasswordsWithBCryptNET/Test/Test.csproj
index 2b842fdabd..b011d844ab 100644
--- a/authorization-dotnet/HowToSecurePasswordsWithBCryptNET/Test/Test.csproj
+++ b/authorization-dotnet/HowToSecurePasswordsWithBCryptNET/Test/Test.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net10.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
 
@@ -9,17 +9,21 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="BCrypt.Net-Next" Version="4.0.3" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.3.2" />
-    <PackageReference Include="xunit" Version="2.4.2" />
-    <PackageReference Include="xunit.runner.visualstudio" Version="2.4.5">
+    <PackageReference Include="BCrypt.Net-Next" Version="4.2.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.10.1" />
+    <PackageReference Include="xunit" Version="2.9.3" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="4.0.0">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       <PrivateAssets>all</PrivateAssets>
     </PackageReference>
-    <PackageReference Include="coverlet.collector" Version="3.1.2">
+    <PackageReference Include="coverlet.collector" Version="10.1.0">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       <PrivateAssets>all</PrivateAssets>
     </PackageReference>
   </ItemGroup>
 
+  <ItemGroup>
+    <ProjectReference Include="..\HowToSecurePasswordsWithBCryptNET\HowToSecurePasswordsWithBCryptNET.csproj" />
+  </ItemGroup>
+
 </Project>