diff --git a/.env.example b/.env.example
new file mode 100644
index 0000000..0193641
--- /dev/null
+++ b/.env.example
@@ -0,0 +1,5 @@
+KEYCLOAK_DB_NAME=keycloak
+KEYCLOAK_DB_USER=keycloak
+KEYCLOAK_DB_PASSWORD=change-me
+KEYCLOAK_ADMIN_USER=admin
+KEYCLOAK_ADMIN_PASSWORD=change-me
diff --git a/.gitignore b/.gitignore
index aa605ff..d78b62a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,5 @@
 .codex
+.env
 WhatsApp Video 2026-04-11 at 20.38.50.mp4
 ChessCubing.App/bin/
 ChessCubing.App/obj/
diff --git a/ChessCubing.App/App.razor b/ChessCubing.App/App.razor
index 983d151..5bdf683 100644
--- a/ChessCubing.App/App.razor
+++ b/ChessCubing.App/App.razor
@@ -1,5 +1,20 @@
-<Router AppAssembly="@typeof(App).Assembly" NotFoundPage="typeof(Pages.NotFound)">
-    <Found Context="routeData">
-        <RouteView RouteData="@routeData" DefaultLayout="@typeof(Layout.MainLayout)" />
-    </Found>
-</Router>
+<CascadingAuthenticationState>
+    <Router AppAssembly="@typeof(App).Assembly" NotFoundPage="typeof(Pages.NotFound)">
+        <Found Context="routeData">
+            <AuthorizeRouteView RouteData="@routeData" DefaultLayout="@typeof(Layout.MainLayout)">
+                <Authorizing>
+                    <main class="rules-shell">
+                        <section class="panel panel-wide cta-panel" style="margin-top: 2rem;">
+                            <p class="eyebrow">Authentification</p>
+                            <h1>Verification de la session en cours...</h1>
+                        </section>
+                    </main>
+                </Authorizing>
+                <NotAuthorized>
+                    <RedirectToLogin />
+                </NotAuthorized>
+            </AuthorizeRouteView>
+            <FocusOnNavigate RouteData="@routeData" Selector="h1" />
+        </Found>
+    </Router>
+</CascadingAuthenticationState>
diff --git a/ChessCubing.App/ChessCubing.App.csproj b/ChessCubing.App/ChessCubing.App.csproj
index dbbd2f6..883d2b4 100644
--- a/ChessCubing.App/ChessCubing.App.csproj
+++ b/ChessCubing.App/ChessCubing.App.csproj
@@ -11,6 +11,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.AspNetCore.Components.WebAssembly" Version="10.0.2" />
+    <PackageReference Include="Microsoft.AspNetCore.Components.WebAssembly.Authentication" Version="10.0.2" />
     <PackageReference Include="Microsoft.AspNetCore.Components.WebAssembly.DevServer" Version="10.0.2" PrivateAssets="all" />
   </ItemGroup>
 
diff --git a/ChessCubing.App/Components/RedirectToLogin.razor b/ChessCubing.App/Components/RedirectToLogin.razor
new file mode 100644
index 0000000..4cb94b6
--- /dev/null
+++ b/ChessCubing.App/Components/RedirectToLogin.razor
@@ -0,0 +1,13 @@
+@inject NavigationManager Navigation
+
+@code {
+    protected override void OnInitialized()
+    {
+        var relativePath = Navigation.ToBaseRelativePath(Navigation.Uri);
+        var returnUrl = string.IsNullOrWhiteSpace(relativePath)
+            ? "/"
+            : relativePath.StartsWith("/", StringComparison.Ordinal) ? relativePath : $"/{relativePath}";
+
+        Navigation.NavigateTo($"authentication/login?returnUrl={Uri.EscapeDataString(returnUrl)}");
+    }
+}
diff --git a/ChessCubing.App/Components/UserAccessBar.razor b/ChessCubing.App/Components/UserAccessBar.razor
new file mode 100644
index 0000000..f75a4ec
--- /dev/null
+++ b/ChessCubing.App/Components/UserAccessBar.razor
@@ -0,0 +1,85 @@
+@using System.Security.Claims
+@inject NavigationManager Navigation
+
+<AuthorizeView>
+    <Authorized Context="authState">
+        <div class="user-access-bar">
+            <div class="user-access-copy">
+                <span class="micro-label">Compte Keycloak</span>
+                <strong>@BuildDisplayName(authState.User)</strong>
+                <span class="user-access-meta">@BuildMeta(authState.User)</span>
+            </div>
+            <div class="user-access-actions">
+                <a class="button ghost small" href="@LogoutHref">Se deconnecter</a>
+            </div>
+        </div>
+    </Authorized>
+    <NotAuthorized>
+        <div class="user-access-bar">
+            <div class="user-access-copy">
+                <span class="micro-label">Compte Keycloak</span>
+                <strong>Connexion requise pour lancer et reprendre les matchs</strong>
+                <span class="user-access-meta">Chaque compte conserve son propre etat de match dans ce navigateur.</span>
+            </div>
+            <div class="user-access-actions">
+                <a class="button primary small" href="@LoginHref">Se connecter</a>
+            </div>
+        </div>
+    </NotAuthorized>
+</AuthorizeView>
+
+@code {
+    private string LoginHref => BuildAuthHref("login", CurrentReturnUrl);
+    private string LogoutHref => BuildAuthHref("logout", "/");
+
+    private string CurrentReturnUrl
+    {
+        get
+        {
+            var relativePath = Navigation.ToBaseRelativePath(Navigation.Uri);
+            if (string.IsNullOrWhiteSpace(relativePath))
+            {
+                return "/";
+            }
+
+            return relativePath.StartsWith("/", StringComparison.Ordinal)
+                ? relativePath
+                : $"/{relativePath}";
+        }
+    }
+
+    private static string BuildAuthHref(string action, string returnUrl)
+        => $"authentication/{action}?returnUrl={Uri.EscapeDataString(returnUrl)}";
+
+    private static string BuildDisplayName(ClaimsPrincipal user)
+        => user.Identity?.Name
+            ?? user.FindFirst("name")?.Value
+            ?? user.FindFirst("preferred_username")?.Value
+            ?? "Utilisateur connecte";
+
+    private static string BuildMeta(ClaimsPrincipal user)
+    {
+        var details = new List<string>();
+        var email = user.FindFirst("email")?.Value;
+        if (!string.IsNullOrWhiteSpace(email))
+        {
+            details.Add(email);
+        }
+
+        var roles = user.FindAll("role")
+            .Select(claim => claim.Value)
+            .Where(value => !string.IsNullOrWhiteSpace(value))
+            .Distinct(StringComparer.OrdinalIgnoreCase)
+            .OrderBy(value => value, StringComparer.OrdinalIgnoreCase)
+            .ToArray();
+
+        if (roles.Length > 0)
+        {
+            details.Add($"Roles : {string.Join(", ", roles)}");
+        }
+
+        return details.Count > 0
+            ? string.Join(" | ", details)
+            : "Session authentifiee via Keycloak.";
+    }
+}
diff --git a/ChessCubing.App/Pages/ApplicationPage.razor b/ChessCubing.App/Pages/ApplicationPage.razor
index b8e469f..4b20a23 100644
--- a/ChessCubing.App/Pages/ApplicationPage.razor
+++ b/ChessCubing.App/Pages/ApplicationPage.razor
@@ -1,5 +1,6 @@
 @page "/application"
 @page "/application.html"
+@attribute [Authorize]
 @inject BrowserBridge Browser
 @inject MatchStore Store
 @inject NavigationManager Navigation
@@ -23,6 +24,7 @@
                 <a class="button ghost" href="index.html">Accueil du site</a>
                 <a class="button secondary" href="reglement.html">Consulter le reglement</a>
             </div>
+            <UserAccessBar />
         </div>
 
         <aside class="hero-preview">
diff --git a/ChessCubing.App/Pages/Authentication.razor b/ChessCubing.App/Pages/Authentication.razor
new file mode 100644
index 0000000..bb9535e
--- /dev/null
+++ b/ChessCubing.App/Pages/Authentication.razor
@@ -0,0 +1,13 @@
+@page "/authentication/{action}"
+
+<main class="rules-shell">
+    <section class="panel panel-wide cta-panel" style="margin-top: 2rem;">
+        <p class="eyebrow">Authentification</p>
+        <RemoteAuthenticatorView Action="@Action" />
+    </section>
+</main>
+
+@code {
+    [Parameter]
+    public string? Action { get; set; }
+}
diff --git a/ChessCubing.App/Pages/ChronoPage.razor b/ChessCubing.App/Pages/ChronoPage.razor
index 7bf2658..f294348 100644
--- a/ChessCubing.App/Pages/ChronoPage.razor
+++ b/ChessCubing.App/Pages/ChronoPage.razor
@@ -1,5 +1,6 @@
 @page "/chrono"
 @page "/chrono.html"
+@attribute [Authorize]
 @implements IAsyncDisposable
 @inject MatchStore Store
 @inject NavigationManager Navigation
diff --git a/ChessCubing.App/Pages/CubePage.razor b/ChessCubing.App/Pages/CubePage.razor
index 343d935..63baee9 100644
--- a/ChessCubing.App/Pages/CubePage.razor
+++ b/ChessCubing.App/Pages/CubePage.razor
@@ -1,5 +1,6 @@
 @page "/cube"
 @page "/cube.html"
+@attribute [Authorize]
 @implements IAsyncDisposable
 @inject BrowserBridge Browser
 @inject MatchStore Store
diff --git a/ChessCubing.App/Pages/Home.razor b/ChessCubing.App/Pages/Home.razor
index 7e8f7ee..a5f7b22 100644
--- a/ChessCubing.App/Pages/Home.razor
+++ b/ChessCubing.App/Pages/Home.razor
@@ -28,6 +28,7 @@
                 <a class="button ghost" href="/ethan/">Ouvrir l'appli d'Ethan</a>
                 <a class="button ghost" href="/brice/">Ouvrir l'appli de Brice</a>
             </div>
+            <UserAccessBar />
         </div>
 
         <aside class="hero-preview">
diff --git a/ChessCubing.App/Pages/RulesPage.razor b/ChessCubing.App/Pages/RulesPage.razor
index 1c4fafc..0e6cb32 100644
--- a/ChessCubing.App/Pages/RulesPage.razor
+++ b/ChessCubing.App/Pages/RulesPage.razor
@@ -32,6 +32,7 @@
                 <a class="button primary" href="application.html">Ouvrir l'application</a>
                 <a class="button secondary" href="index.html">Retour a l'accueil</a>
             </div>
+            <UserAccessBar />
         </div>
 
         <aside class="hero-preview">
diff --git a/ChessCubing.App/Program.cs b/ChessCubing.App/Program.cs
index be6caa2..cbebd12 100644
--- a/ChessCubing.App/Program.cs
+++ b/ChessCubing.App/Program.cs
@@ -2,13 +2,57 @@ using ChessCubing.App;
 using ChessCubing.App.Services;
 using Microsoft.AspNetCore.Components.Web;
 using Microsoft.AspNetCore.Components.WebAssembly.Hosting;
+using Microsoft.AspNetCore.Components.WebAssembly.Authentication;
 
 var builder = WebAssemblyHostBuilder.CreateDefault(args);
 builder.RootComponents.Add<App>("#app");
 builder.RootComponents.Add<HeadOutlet>("head::after");
 
+var keycloakAuthority = builder.Configuration["Keycloak:Authority"] ?? "/auth/realms/chesscubing";
+var keycloakClientId = builder.Configuration["Keycloak:ClientId"] ?? "chesscubing-web";
+var keycloakResponseType = builder.Configuration["Keycloak:ResponseType"] ?? "code";
+var postLogoutRedirectUri = builder.Configuration["Keycloak:PostLogoutRedirectUri"] ?? "/";
+var defaultScopes = builder.Configuration
+    .GetSection("Keycloak:DefaultScopes")
+    .GetChildren()
+    .Select(child => child.Value)
+    .Where(value => !string.IsNullOrWhiteSpace(value))
+    .Cast<string>()
+    .ToArray();
+
 builder.Services.AddScoped(_ => new HttpClient { BaseAddress = new Uri(builder.HostEnvironment.BaseAddress) });
+builder.Services
+    .AddOidcAuthentication(options =>
+    {
+        options.ProviderOptions.Authority = ResolveUri(builder.HostEnvironment.BaseAddress, keycloakAuthority);
+        options.ProviderOptions.ClientId = keycloakClientId;
+        options.ProviderOptions.ResponseType = keycloakResponseType;
+        options.ProviderOptions.RedirectUri = ResolveUri(builder.HostEnvironment.BaseAddress, "authentication/login-callback");
+        options.ProviderOptions.PostLogoutRedirectUri = ResolveUri(builder.HostEnvironment.BaseAddress, postLogoutRedirectUri);
+
+        options.ProviderOptions.DefaultScopes.Clear();
+        foreach (var scope in defaultScopes.Length == 0 ? ["openid", "profile", "email"] : defaultScopes)
+        {
+            options.ProviderOptions.DefaultScopes.Add(scope);
+        }
+
+        options.UserOptions.NameClaim = "preferred_username";
+        options.UserOptions.RoleClaim = "role";
+    })
+    .AddAccountClaimsPrincipalFactory<KeycloakAccountFactory>();
+
 builder.Services.AddScoped<BrowserBridge>();
+builder.Services.AddScoped<UserSession>();
 builder.Services.AddScoped<MatchStore>();
 
 await builder.Build().RunAsync();
+
+static string ResolveUri(string baseAddress, string value)
+{
+    if (Uri.TryCreate(value, UriKind.Absolute, out var absoluteUri))
+    {
+        return absoluteUri.ToString();
+    }
+
+    return new Uri(new Uri(baseAddress), value).ToString();
+}
diff --git a/ChessCubing.App/Services/BrowserBridge.cs b/ChessCubing.App/Services/BrowserBridge.cs
index 150d833..19e6f97 100644
--- a/ChessCubing.App/Services/BrowserBridge.cs
+++ b/ChessCubing.App/Services/BrowserBridge.cs
@@ -10,14 +10,14 @@ public sealed class BrowserBridge(IJSRuntime jsRuntime)
     public ValueTask SetBodyStateAsync(string? page, string? bodyClass)
         => jsRuntime.InvokeVoidAsync("chesscubingPage.setBodyState", page, bodyClass ?? string.Empty);
 
-    public ValueTask<string?> ReadMatchJsonAsync()
-        => jsRuntime.InvokeAsync<string?>("chesscubingStorage.getMatchState", MatchStore.StorageKey, MatchStore.WindowNameKey);
+    public ValueTask<string?> ReadMatchJsonAsync(string storageKey, string windowNameKey)
+        => jsRuntime.InvokeAsync<string?>("chesscubingStorage.getMatchState", storageKey, windowNameKey);
 
-    public ValueTask WriteMatchJsonAsync(string json)
-        => jsRuntime.InvokeVoidAsync("chesscubingStorage.setMatchState", MatchStore.StorageKey, MatchStore.WindowNameKey, json);
+    public ValueTask WriteMatchJsonAsync(string storageKey, string windowNameKey, string json)
+        => jsRuntime.InvokeVoidAsync("chesscubingStorage.setMatchState", storageKey, windowNameKey, json);
 
-    public ValueTask ClearMatchAsync()
-        => jsRuntime.InvokeVoidAsync("chesscubingStorage.clearMatchState", MatchStore.StorageKey);
+    public ValueTask ClearMatchAsync(string storageKey, string windowNameKey)
+        => jsRuntime.InvokeVoidAsync("chesscubingStorage.clearMatchState", storageKey, windowNameKey);
 
     public ValueTask<bool> PlayCubePhaseAlertAsync()
         => jsRuntime.InvokeAsync<bool>("chesscubingAudio.playCubePhaseAlert");
diff --git a/ChessCubing.App/Services/KeycloakAccountFactory.cs b/ChessCubing.App/Services/KeycloakAccountFactory.cs
new file mode 100644
index 0000000..382e263
--- /dev/null
+++ b/ChessCubing.App/Services/KeycloakAccountFactory.cs
@@ -0,0 +1,53 @@
+using System.Security.Claims;
+using System.Text.Json;
+using Microsoft.AspNetCore.Components.WebAssembly.Authentication;
+using Microsoft.AspNetCore.Components.WebAssembly.Authentication.Internal;
+
+namespace ChessCubing.App.Services;
+
+public sealed class KeycloakAccountFactory(IAccessTokenProviderAccessor accessor)
+    : AccountClaimsPrincipalFactory<RemoteUserAccount>(accessor)
+{
+    public override async ValueTask<ClaimsPrincipal> CreateUserAsync(
+        RemoteUserAccount account,
+        RemoteAuthenticationUserOptions options)
+    {
+        var user = await base.CreateUserAsync(account, options);
+        if (user.Identity is not ClaimsIdentity identity || !identity.IsAuthenticated)
+        {
+            return user;
+        }
+
+        var roleClaimType = options.RoleClaim ?? "role";
+        var existingRoles = identity.FindAll(roleClaimType)
+            .Select(claim => claim.Value)
+            .ToHashSet(StringComparer.OrdinalIgnoreCase);
+
+        foreach (var role in ReadRealmRoles(account))
+        {
+            if (existingRoles.Add(role))
+            {
+                identity.AddClaim(new Claim(roleClaimType, role));
+            }
+        }
+
+        return user;
+    }
+
+    private static IEnumerable<string> ReadRealmRoles(RemoteUserAccount account)
+    {
+        if (!account.AdditionalProperties.TryGetValue("realm_access", out var realmAccessValue) ||
+            realmAccessValue is not JsonElement realmAccessElement ||
+            realmAccessElement.ValueKind != JsonValueKind.Object ||
+            !realmAccessElement.TryGetProperty("roles", out var rolesElement) ||
+            rolesElement.ValueKind != JsonValueKind.Array)
+        {
+            return [];
+        }
+
+        return rolesElement.EnumerateArray()
+            .Where(item => item.ValueKind == JsonValueKind.String)
+            .Select(item => item.GetString())
+            .OfType<string>();
+    }
+}
diff --git a/ChessCubing.App/Services/MatchStore.cs b/ChessCubing.App/Services/MatchStore.cs
index 49d3d4d..f5b6682 100644
--- a/ChessCubing.App/Services/MatchStore.cs
+++ b/ChessCubing.App/Services/MatchStore.cs
@@ -4,10 +4,10 @@ using ChessCubing.App.Models;
 
 namespace ChessCubing.App.Services;
 
-public sealed class MatchStore(BrowserBridge browser)
+public sealed class MatchStore(BrowserBridge browser, UserSession userSession)
 {
-    public const string StorageKey = "chesscubing-arena-state-v2";
-    public const string WindowNameKey = "chesscubing-arena-state-v2:";
+    public const string StorageKeyPrefix = "chesscubing-arena-state-v3";
+    public const string WindowNameKeyPrefix = "chesscubing-arena-state-v3";
 
     private static readonly JsonSerializerOptions JsonOptions = new(JsonSerializerDefaults.Web)
     {
@@ -16,6 +16,8 @@ public sealed class MatchStore(BrowserBridge browser)
 
     private bool _dirty;
     private long _lastPersistedAt;
+    private string? _activeStorageKey;
+    private string? _activeWindowNameKey;
 
     public MatchState? Current { get; private set; }
 
@@ -23,6 +25,7 @@ public sealed class MatchStore(BrowserBridge browser)
 
     public async Task EnsureLoadedAsync()
     {
+        var storageScope = await SyncStorageScopeAsync();
         if (IsLoaded)
         {
             return;
@@ -30,7 +33,7 @@ public sealed class MatchStore(BrowserBridge browser)
 
         try
         {
-            var raw = await browser.ReadMatchJsonAsync();
+            var raw = await browser.ReadMatchJsonAsync(storageScope.StorageKey, storageScope.WindowNameKey);
             if (!string.IsNullOrWhiteSpace(raw))
             {
                 var parsed = JsonSerializer.Deserialize<MatchState>(raw, JsonOptions);
@@ -61,6 +64,7 @@ public sealed class MatchStore(BrowserBridge browser)
 
     public async Task SaveAsync()
     {
+        var storageScope = await SyncStorageScopeAsync();
         if (!IsLoaded)
         {
             return;
@@ -68,14 +72,14 @@ public sealed class MatchStore(BrowserBridge browser)
 
         if (Current is null)
         {
-            await browser.ClearMatchAsync();
+            await browser.ClearMatchAsync(storageScope.StorageKey, storageScope.WindowNameKey);
             _dirty = false;
             _lastPersistedAt = MatchEngine.NowUnixMs();
             return;
         }
 
         var json = JsonSerializer.Serialize(Current, JsonOptions);
-        await browser.WriteMatchJsonAsync(json);
+        await browser.WriteMatchJsonAsync(storageScope.StorageKey, storageScope.WindowNameKey, json);
         _dirty = false;
         _lastPersistedAt = MatchEngine.NowUnixMs();
     }
@@ -97,10 +101,27 @@ public sealed class MatchStore(BrowserBridge browser)
 
     public async Task ClearAsync()
     {
+        var storageScope = await SyncStorageScopeAsync();
         Current = null;
         IsLoaded = true;
         _dirty = false;
         _lastPersistedAt = MatchEngine.NowUnixMs();
-        await browser.ClearMatchAsync();
+        await browser.ClearMatchAsync(storageScope.StorageKey, storageScope.WindowNameKey);
+    }
+
+    private async ValueTask<UserStorageScope> SyncStorageScopeAsync()
+    {
+        var storageScope = await userSession.GetStorageScopeAsync();
+        if (_activeStorageKey is not null &&
+            (_activeStorageKey != storageScope.StorageKey || _activeWindowNameKey != storageScope.WindowNameKey))
+        {
+            Current = null;
+            IsLoaded = false;
+            _dirty = false;
+        }
+
+        _activeStorageKey = storageScope.StorageKey;
+        _activeWindowNameKey = storageScope.WindowNameKey;
+        return storageScope;
     }
 }
diff --git a/ChessCubing.App/Services/UserSession.cs b/ChessCubing.App/Services/UserSession.cs
new file mode 100644
index 0000000..19a66a5
--- /dev/null
+++ b/ChessCubing.App/Services/UserSession.cs
@@ -0,0 +1,39 @@
+using System.Security.Claims;
+using Microsoft.AspNetCore.Components.Authorization;
+
+namespace ChessCubing.App.Services;
+
+public sealed class UserSession(AuthenticationStateProvider authenticationStateProvider)
+{
+    public async ValueTask<UserStorageScope> GetStorageScopeAsync()
+    {
+        var authState = await authenticationStateProvider.GetAuthenticationStateAsync();
+        var userId = ResolveUserId(authState.User);
+
+        return new UserStorageScope(
+            $"{MatchStore.StorageKeyPrefix}:{userId}",
+            $"{MatchStore.WindowNameKeyPrefix}:{userId}:");
+    }
+
+    private static string ResolveUserId(ClaimsPrincipal user)
+    {
+        if (user.Identity?.IsAuthenticated != true)
+        {
+            return "anonymous";
+        }
+
+        var rawIdentifier = user.FindFirst("sub")?.Value
+            ?? user.FindFirst(ClaimTypes.NameIdentifier)?.Value
+            ?? user.FindFirst("preferred_username")?.Value
+            ?? user.Identity?.Name;
+
+        if (string.IsNullOrWhiteSpace(rawIdentifier))
+        {
+            return "authenticated";
+        }
+
+        return Uri.EscapeDataString(rawIdentifier.Trim());
+    }
+}
+
+public readonly record struct UserStorageScope(string StorageKey, string WindowNameKey);
diff --git a/ChessCubing.App/_Imports.razor b/ChessCubing.App/_Imports.razor
index dc2c25b..44b7112 100644
--- a/ChessCubing.App/_Imports.razor
+++ b/ChessCubing.App/_Imports.razor
@@ -4,8 +4,11 @@
 @using ChessCubing.App.Components
 @using ChessCubing.App.Models
 @using ChessCubing.App.Services
+@using Microsoft.AspNetCore.Authorization
+@using Microsoft.AspNetCore.Components.Authorization
 @using Microsoft.AspNetCore.Components
 @using Microsoft.AspNetCore.Components.Forms
 @using Microsoft.AspNetCore.Components.Routing
 @using Microsoft.AspNetCore.Components.Web
+@using Microsoft.AspNetCore.Components.WebAssembly.Authentication
 @using Microsoft.JSInterop
diff --git a/ChessCubing.App/wwwroot/appsettings.json b/ChessCubing.App/wwwroot/appsettings.json
new file mode 100644
index 0000000..b783d6a
--- /dev/null
+++ b/ChessCubing.App/wwwroot/appsettings.json
@@ -0,0 +1,13 @@
+{
+  "Keycloak": {
+    "Authority": "/auth/realms/chesscubing",
+    "ClientId": "chesscubing-web",
+    "ResponseType": "code",
+    "PostLogoutRedirectUri": "/",
+    "DefaultScopes": [
+      "openid",
+      "profile",
+      "email"
+    ]
+  }
+}
diff --git a/ChessCubing.App/wwwroot/js/chesscubing-interop.js b/ChessCubing.App/wwwroot/js/chesscubing-interop.js
index c1de074..bb0abb6 100644
--- a/ChessCubing.App/wwwroot/js/chesscubing-interop.js
+++ b/ChessCubing.App/wwwroot/js/chesscubing-interop.js
@@ -146,14 +146,16 @@
       }
     },
 
-    clearMatchState(storageKey) {
+    clearMatchState(storageKey, windowNameKey) {
       try {
         window.localStorage.removeItem(storageKey);
       } catch {
       }
 
       try {
-        window.name = "";
+        if (window.name && window.name.startsWith(windowNameKey)) {
+          window.name = "";
+        }
       } catch {
       }
     },
diff --git a/README.md b/README.md
index ccdd607..18b9048 100644
--- a/README.md
+++ b/README.md
@@ -22,11 +22,30 @@ Le coeur de l'application se trouve dans `ChessCubing.App/`.
 - `ChessCubing.App/Pages/` : pages Razor du site et de l'application
 - `ChessCubing.App/Services/MatchEngine.cs` : logique metier des matchs
 - `ChessCubing.App/Services/MatchStore.cs` : persistance navigateur
+- `ChessCubing.App/Services/KeycloakAccountFactory.cs` : adaptation des roles Keycloak vers les claims Blazor
 - `ChessCubing.App/wwwroot/` : assets statiques, manifeste, PDFs, appli Ethan
-- `docker-compose.yml` + `Dockerfile` : build Blazor puis service via nginx
+- `keycloak/realm/chesscubing-realm.json` : realm importable avec client OIDC et roles
+- `docker-compose.yml` + `Dockerfile` : build Blazor, service via nginx et stack Keycloak/Postgres
 
 Le projet continue a exposer les routes historiques `index.html`, `application.html`, `chrono.html`, `cube.html` et `reglement.html`.
 
+## Authentification Keycloak
+
+L'application embarque maintenant une authentification OpenID Connect basee sur Keycloak.
+
+- les pages `application.html`, `chrono.html` et `cube.html` demandent une connexion
+- la page d'accueil et la page reglement affichent l'etat de session courant
+- les roles Keycloak du realm sont exposes dans l'application
+- l'etat du match est isole par utilisateur dans le navigateur grace a une cle de stockage derivee du compte connecte
+
+Le realm importe par defaut :
+
+- realm : `chesscubing`
+- client public OIDC : `chesscubing-web`
+- roles de realm : `admin`, `organizer`, `player`
+
+La gestion des utilisateurs se fait ensuite dans la console d'administration Keycloak.
+
 ## Demarrage local
 
 ### Avec Docker
@@ -38,6 +57,17 @@ docker compose up -d --build
 
 L'application est ensuite disponible sur `http://localhost:8080`.
 
+La console Keycloak est servie via le meme nginx sur `http://localhost:8080/auth/admin/`.
+
+Identifiants d'administration par defaut pour le premier demarrage local :
+
+- utilisateur : `admin`
+- mot de passe : `admin`
+
+Ces valeurs peuvent etre surchargees via les variables d'environnement de `.env.example`.
+
+Si vous voulez reimporter completement le realm fourni dans `keycloak/realm/`, il faut repartir d'une base vide, par exemple avec `docker compose down -v` avant le redemarrage.
+
 ### Avec .NET 10
 
 ```bash
@@ -45,6 +75,8 @@ dotnet restore ChessCubing.App/ChessCubing.App.csproj
 dotnet run --project ChessCubing.App/ChessCubing.App.csproj
 ```
 
+Le mode Docker reste la voie recommandee pour cette integration, car nginx y reverse-proxy egalement Keycloak sous `/auth/`.
+
 ## Deploiement dans un LXC Proxmox
 
 Deux scripts Bash permettent de creer un conteneur LXC Debian sur Proxmox puis de le mettre a jour depuis Git.
@@ -56,6 +88,8 @@ Prerrequis sur la machine qui lance les scripts :
 
 Le deploiement dans le LXC n'utilise pas Docker. Le script clone le depot, publie l'application Blazor dans le conteneur, puis sert le resultat via `nginx`.
 
+Attention : la pile Keycloak fournie ici est actuellement prete a l'emploi dans la stack Docker du projet. Les scripts LXC existants ne provisionnent pas encore automatiquement Keycloak ni sa base Postgres.
+
 ### Installer un nouveau LXC
 
 ```bash
@@ -95,6 +129,9 @@ bash -c "$(curl -fsSL https://git.jeannerot.fr/christophe/chesscubing/raw/branch
 - `ChessCubing.App/Pages/CubePage.razor` : phase cube
 - `ChessCubing.App/Pages/RulesPage.razor` : synthese du reglement
 - `ChessCubing.App/Services/MatchEngine.cs` : regles de jeu et transitions
+- `ChessCubing.App/Services/KeycloakAccountFactory.cs` : transformation des roles Keycloak en claims Blazor
+- `ChessCubing.App/wwwroot/appsettings.json` : configuration OIDC du client WebAssembly
+- `keycloak/realm/chesscubing-realm.json` : realm, roles et client Keycloak importes
 - `docker-compose.yml` + `Dockerfile` : execution locale
 - `scripts/install-proxmox-lxc.sh` : creation et deploiement d'un LXC Proxmox
 - `scripts/update-proxmox-lxc.sh` : mise a jour d'un LXC existant depuis Git
diff --git a/docker-compose.yml b/docker-compose.yml
index 66917dc..4abb429 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -2,6 +2,52 @@ services:
   web:
     build: .
     container_name: chesscubing-web
+    depends_on:
+      keycloak:
+        condition: service_started
     ports:
       - "8080:80"
     restart: unless-stopped
+
+  keycloak:
+    image: quay.io/keycloak/keycloak:26.1.2
+    container_name: chesscubing-keycloak
+    command: ["start-dev", "--import-realm"]
+    environment:
+      KC_DB: postgres
+      KC_DB_URL_HOST: postgres
+      KC_DB_URL_PORT: 5432
+      KC_DB_URL_DATABASE: ${KEYCLOAK_DB_NAME:-keycloak}
+      KC_DB_USERNAME: ${KEYCLOAK_DB_USER:-keycloak}
+      KC_DB_PASSWORD: ${KEYCLOAK_DB_PASSWORD:-keycloak}
+      KC_BOOTSTRAP_ADMIN_USERNAME: ${KEYCLOAK_ADMIN_USER:-admin}
+      KC_BOOTSTRAP_ADMIN_PASSWORD: ${KEYCLOAK_ADMIN_PASSWORD:-admin}
+      KC_PROXY_HEADERS: xforwarded
+      KC_HOSTNAME: http://localhost:8080/auth
+      KC_HTTP_RELATIVE_PATH: /auth
+      KC_HOSTNAME_STRICT: "false"
+    volumes:
+      - ./keycloak/realm:/opt/keycloak/data/import:ro
+    depends_on:
+      postgres:
+        condition: service_healthy
+    restart: unless-stopped
+
+  postgres:
+    image: postgres:16-alpine
+    container_name: chesscubing-keycloak-db
+    environment:
+      POSTGRES_DB: ${KEYCLOAK_DB_NAME:-keycloak}
+      POSTGRES_USER: ${KEYCLOAK_DB_USER:-keycloak}
+      POSTGRES_PASSWORD: ${KEYCLOAK_DB_PASSWORD:-keycloak}
+    volumes:
+      - keycloak-postgres:/var/lib/postgresql/data
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U ${KEYCLOAK_DB_USER:-keycloak} -d ${KEYCLOAK_DB_NAME:-keycloak}"]
+      interval: 10s
+      timeout: 5s
+      retries: 5
+    restart: unless-stopped
+
+volumes:
+  keycloak-postgres:
diff --git a/keycloak/realm/chesscubing-realm.json b/keycloak/realm/chesscubing-realm.json
new file mode 100644
index 0000000..b78bd10
--- /dev/null
+++ b/keycloak/realm/chesscubing-realm.json
@@ -0,0 +1,62 @@
+{
+  "realm": "chesscubing",
+  "enabled": true,
+  "displayName": "ChessCubing",
+  "registrationAllowed": false,
+  "rememberMe": true,
+  "resetPasswordAllowed": true,
+  "loginWithEmailAllowed": true,
+  "duplicateEmailsAllowed": false,
+  "editUsernameAllowed": false,
+  "sslRequired": "external",
+  "roles": {
+    "realm": [
+      {
+        "name": "admin",
+        "description": "Administrateur ChessCubing"
+      },
+      {
+        "name": "organizer",
+        "description": "Organisateur de rencontre"
+      },
+      {
+        "name": "player",
+        "description": "Joueur ChessCubing"
+      }
+    ]
+  },
+  "clients": [
+    {
+      "clientId": "chesscubing-web",
+      "name": "ChessCubing Web",
+      "description": "Client OIDC public pour l'application Blazor WebAssembly.",
+      "enabled": true,
+      "protocol": "openid-connect",
+      "publicClient": true,
+      "standardFlowEnabled": true,
+      "directAccessGrantsEnabled": false,
+      "serviceAccountsEnabled": false,
+      "implicitFlowEnabled": false,
+      "frontchannelLogout": true,
+      "rootUrl": "http://localhost:8080/",
+      "baseUrl": "http://localhost:8080/",
+      "redirectUris": [
+        "http://localhost:8080/*"
+      ],
+      "webOrigins": [
+        "http://localhost:8080"
+      ],
+      "attributes": {
+        "pkce.code.challenge.method": "S256",
+        "post.logout.redirect.uris": "http://localhost:8080/*"
+      },
+      "defaultClientScopes": [
+        "web-origins",
+        "acr",
+        "profile",
+        "roles",
+        "email"
+      ]
+    }
+  ]
+}
diff --git a/nginx.conf b/nginx.conf
index 7e2d0dc..442f095 100644
--- a/nginx.conf
+++ b/nginx.conf
@@ -21,6 +21,16 @@ server {
     try_files $uri $uri/ /brice/index.html;
   }
 
+  location /auth/ {
+    proxy_http_version 1.1;
+    proxy_pass http://keycloak:8080/auth/;
+    proxy_set_header Host $http_host;
+    proxy_set_header X-Forwarded-Host $http_host;
+    proxy_set_header X-Forwarded-Proto $scheme;
+    proxy_set_header X-Forwarded-Port $server_port;
+    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+  }
+
   location / {
     try_files $uri $uri/ /index.html;
   }
diff --git a/styles.css b/styles.css
index bfd0a4e..a626911 100644
--- a/styles.css
+++ b/styles.css
@@ -1047,6 +1047,36 @@ body[data-page="cube"] .zone-button.cube-hold-ready::after {
   margin-top: 1.2rem;
 }
 
+.user-access-bar {
+  display: grid;
+  gap: 0.9rem;
+  margin-top: 1rem;
+  padding: 1rem;
+  border-radius: 24px;
+  border: 1px solid var(--panel-border);
+  background: rgba(12, 14, 20, 0.76);
+}
+
+.user-access-copy {
+  display: grid;
+  gap: 0.35rem;
+}
+
+.user-access-copy strong {
+  font-size: 1.02rem;
+}
+
+.user-access-meta {
+  color: var(--muted);
+  line-height: 1.45;
+}
+
+.user-access-actions {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 0.75rem;
+}
+
 .rule-metrics {
   display: grid;
   grid-template-columns: repeat(2, minmax(0, 1fr));
@@ -1310,12 +1340,23 @@ body[data-page="cube"] .zone-button.cube-hold-ready::after {
     text-align: center;
   }
 
+  .user-access-bar {
+    grid-template-columns: 1fr;
+  }
+
   .brand-link,
   .utility-button {
     justify-self: center;
   }
 }
 
+@media (min-width: 720px) {
+  .user-access-bar {
+    grid-template-columns: minmax(0, 1fr) auto;
+    align-items: center;
+  }
+}
+
 @media (max-width: 900px) {
   .phase-body {
     overflow-y: auto;