diff --git a/Directory.Packages.props b/Directory.Packages.props
index a1075dac..c90bf9c6 100644
--- a/Directory.Packages.props
+++ b/Directory.Packages.props
@@ -25,6 +25,7 @@
     <PackageVersion Include="Microsoft.AspNetCore.DataProtection"                   Version="10.0.8"          />
     <PackageVersion Include="Microsoft.Bcl.Cryptography"                            Version="10.0.8"          />
     <PackageVersion Include="Microsoft.Bcl.HashCode"                                Version="6.0.0"           />
+    <PackageVersion Include="Microsoft.Bcl.Memory"                                  Version="10.0.8"          />
     <PackageVersion Include="Microsoft.Extensions.Caching.Memory"                   Version="10.0.8"          />
     <PackageVersion Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="10.0.8"          />
     <PackageVersion Include="Microsoft.Extensions.Hosting.Abstractions"             Version="10.0.8"          />
diff --git a/src/OpenIddict.Client.AspNetCore/OpenIddictClientAspNetCoreHandlers.cs b/src/OpenIddict.Client.AspNetCore/OpenIddictClientAspNetCoreHandlers.cs
index 82f213d3..a26e73fb 100644
--- a/src/OpenIddict.Client.AspNetCore/OpenIddictClientAspNetCoreHandlers.cs
+++ b/src/OpenIddict.Client.AspNetCore/OpenIddictClientAspNetCoreHandlers.cs
@@ -5,6 +5,7 @@
  */
 
 using System.Buffers.Binary;
+using System.Buffers.Text;
 using System.Collections.Immutable;
 using System.ComponentModel;
 using System.Diagnostics;
@@ -18,7 +19,6 @@ using Microsoft.AspNetCore.Diagnostics;
 using Microsoft.AspNetCore.Http.Extensions;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
-using Microsoft.IdentityModel.Tokens;
 using Microsoft.Net.Http.Headers;
 using Properties = OpenIddict.Client.AspNetCore.OpenIddictClientAspNetCoreConstants.Properties;
 
@@ -421,7 +421,7 @@ public static partial class OpenIddictClientAspNetCoreHandlers
             try
             {
                 // Extract the payload and validate the version marker.
-                var payload = Base64UrlEncoder.DecodeBytes(value);
+                var payload = Base64Url.DecodeFromChars(value);
                 if (payload.Length < (1 + sizeof(uint)) || payload[0] is not 0x01)
                 {
                     context.Reject(
@@ -818,7 +818,7 @@ public static partial class OpenIddictClientAspNetCoreHandlers
             Debug.Assert(written == count, SR.FormatID4016(written, count));
 
             // Add the correlation cookie to the response headers.
-            response.Cookies.Append(name, Base64UrlEncoder.Encode(payload), options);
+            response.Cookies.Append(name, Base64Url.EncodeToString(payload), options);
 
             return ValueTask.CompletedTask;
         }
@@ -1041,7 +1041,7 @@ public static partial class OpenIddictClientAspNetCoreHandlers
             Debug.Assert(written == count, SR.FormatID4016(written, count));
 
             // Add the correlation cookie to the response headers.
-            response.Cookies.Append(name, Base64UrlEncoder.Encode(payload), options);
+            response.Cookies.Append(name, Base64Url.EncodeToString(payload), options);
 
             return ValueTask.CompletedTask;
         }
diff --git a/src/OpenIddict.Client.DataProtection/OpenIddictClientDataProtectionHandlers.Protection.cs b/src/OpenIddict.Client.DataProtection/OpenIddictClientDataProtectionHandlers.Protection.cs
index 4b8975ec..b8eb47a7 100644
--- a/src/OpenIddict.Client.DataProtection/OpenIddictClientDataProtectionHandlers.Protection.cs
+++ b/src/OpenIddict.Client.DataProtection/OpenIddictClientDataProtectionHandlers.Protection.cs
@@ -4,12 +4,12 @@
  * the license and the contributors participating to this project.
  */
 
+using System.Buffers.Text;
 using System.Collections.Immutable;
 using System.Security.Claims;
 using Microsoft.AspNetCore.DataProtection;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
-using Microsoft.IdentityModel.Tokens;
 using static OpenIddict.Client.DataProtection.OpenIddictClientDataProtectionConstants.Purposes;
 using static OpenIddict.Client.OpenIddictClientHandlers.Protection;
 using Schemes = OpenIddict.Client.DataProtection.OpenIddictClientDataProtectionConstants.Purposes.Schemes;
@@ -134,7 +134,7 @@ public static partial class OpenIddictClientDataProtectionHandlers
 
                     try
                     {
-                        using var buffer = new MemoryStream(protector.Unprotect(Base64UrlEncoder.DecodeBytes(context.Token)));
+                        using var buffer = new MemoryStream(protector.Unprotect(Base64Url.DecodeFromChars(context.Token)));
                         using var reader = new BinaryReader(buffer);
 
                         // Note: since the data format relies on a data protector using different "purposes" strings
@@ -247,7 +247,7 @@ public static partial class OpenIddictClientDataProtectionHandlers
 
                 _options.CurrentValue.Formatter.WriteToken(writer, context.Principal);
 
-                context.Token = Base64UrlEncoder.Encode(protector.Protect(buffer.ToArray()));
+                context.Token = Base64Url.EncodeToString(protector.Protect(buffer.ToArray()));
 
                 context.Logger.LogTrace(6016, SR.GetResourceString(SR.ID6016), context.TokenType,
                     context.Token, context.Principal.Claims);
diff --git a/src/OpenIddict.Client.Owin/OpenIddictClientOwinHandlers.cs b/src/OpenIddict.Client.Owin/OpenIddictClientOwinHandlers.cs
index 24714ad7..af6d3e70 100644
--- a/src/OpenIddict.Client.Owin/OpenIddictClientOwinHandlers.cs
+++ b/src/OpenIddict.Client.Owin/OpenIddictClientOwinHandlers.cs
@@ -5,6 +5,7 @@
  */
 
 using System.Buffers.Binary;
+using System.Buffers.Text;
 using System.Collections.Immutable;
 using System.ComponentModel;
 using System.Diagnostics;
@@ -15,7 +16,6 @@ using System.Text.Json;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
 using Microsoft.Extensions.Primitives;
-using Microsoft.IdentityModel.Tokens;
 using Owin;
 using static OpenIddict.Client.Owin.OpenIddictClientOwinConstants;
 using Properties = OpenIddict.Client.Owin.OpenIddictClientOwinConstants.Properties;
@@ -432,7 +432,7 @@ public static partial class OpenIddictClientOwinHandlers
             try
             {
                 // Extract the payload and validate the version marker.
-                var payload = Base64UrlEncoder.DecodeBytes(value);
+                var payload = Base64Url.DecodeFromChars(value);
                 if (payload.Length < (1 + sizeof(uint)) || payload[0] is not 0x01)
                 {
                     context.Reject(
@@ -846,7 +846,7 @@ public static partial class OpenIddictClientOwinHandlers
                 _options.CurrentValue.CookieOptions);
 
             // Add the correlation cookie to the response headers.
-            manager.AppendResponseCookie(response.Context, name, Base64UrlEncoder.Encode(payload), new CookieOptions
+            manager.AppendResponseCookie(response.Context, name, Base64Url.EncodeToString(payload), new CookieOptions
             {
                 Domain = options.Domain,
                 HttpOnly = options.HttpOnly,
@@ -1090,7 +1090,7 @@ public static partial class OpenIddictClientOwinHandlers
                 _options.CurrentValue.CookieOptions);
 
             // Add the correlation cookie to the response headers.
-            manager.AppendResponseCookie(response.Context, name, Base64UrlEncoder.Encode(payload), new CookieOptions
+            manager.AppendResponseCookie(response.Context, name, Base64Url.EncodeToString(payload), new CookieOptions
             {
                 Domain = options.Domain,
                 HttpOnly = options.HttpOnly,
diff --git a/src/OpenIddict.Client.SystemIntegration/OpenIddictClientSystemIntegrationConfiguration.cs b/src/OpenIddict.Client.SystemIntegration/OpenIddictClientSystemIntegrationConfiguration.cs
index 06aa54f7..867b62f8 100644
--- a/src/OpenIddict.Client.SystemIntegration/OpenIddictClientSystemIntegrationConfiguration.cs
+++ b/src/OpenIddict.Client.SystemIntegration/OpenIddictClientSystemIntegrationConfiguration.cs
@@ -4,6 +4,7 @@
  * the license and the contributors participating to this project.
  */
 
+using System.Buffers.Text;
 using System.ComponentModel;
 using System.IO.Pipes;
 using System.Net;
@@ -14,7 +15,6 @@ using System.Text;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
 using Microsoft.Extensions.Options;
-using Microsoft.IdentityModel.Tokens;
 using static OpenIddict.Client.SystemIntegration.OpenIddictClientSystemIntegrationAuthenticationMode;
 
 namespace OpenIddict.Client.SystemIntegration;
@@ -96,13 +96,13 @@ public sealed class OpenIddictClientSystemIntegrationConfiguration : IConfigureO
             // Note: only the left-most half of the hash is used to limit the length of the resulting discriminator,
             // which is required on platforms like macOS, where the name of pipes is always prefixed with a static part
             // (e.g /var/folders/5j/jjxtct5j1gvg35z6sdh2fz0w0000gn/T/CoreFxPipe_) and must not exceed 104 characters.
-            options.ApplicationDiscriminator = Base64UrlEncoder.Encode(digest, 0, digest.Length / 2);
+            options.ApplicationDiscriminator = Base64Url.EncodeToString(digest.AsSpan(0, digest.Length / 2));
         }
 
         // If no explicit instance identifier was specified, use a 96-bit random identifier.
         if (string.IsNullOrEmpty(options.InstanceIdentifier))
         {
-            options.InstanceIdentifier = Base64UrlEncoder.Encode(RandomNumberGenerator.GetBytes(count: 96 / 8));
+            options.InstanceIdentifier = Base64Url.EncodeToString(RandomNumberGenerator.GetBytes(count: 96 / 8));
         }
 
         // If no explicit pipe name was specified, build one using the application discriminator.
diff --git a/src/OpenIddict.Client.SystemNetHttp/OpenIddictClientSystemNetHttpContext.cs b/src/OpenIddict.Client.SystemNetHttp/OpenIddictClientSystemNetHttpContext.cs
index 585cf772..8823c8eb 100644
--- a/src/OpenIddict.Client.SystemNetHttp/OpenIddictClientSystemNetHttpContext.cs
+++ b/src/OpenIddict.Client.SystemNetHttp/OpenIddictClientSystemNetHttpContext.cs
@@ -4,11 +4,11 @@
  * the license and the contributors participating to this project.
  */
 
+using System.Buffers.Text;
 using System.ComponentModel;
 using System.Security.Cryptography;
 using System.Security.Cryptography.X509Certificates;
 using System.Text;
-using Microsoft.IdentityModel.Tokens;
 
 namespace OpenIddict.Client.SystemNetHttp;
 
@@ -61,6 +61,6 @@ public sealed class OpenIddictClientSystemNetHttpContext
 
         algorithm.TransformFinalBlock([], 0, 0);
 
-        return Base64UrlEncoder.Encode(algorithm.Hash);
+        return Base64Url.EncodeToString(algorithm.Hash);
     }
 }
diff --git a/src/OpenIddict.Client/OpenIddict.Client.csproj b/src/OpenIddict.Client/OpenIddict.Client.csproj
index a244ca3d..590c71f9 100644
--- a/src/OpenIddict.Client/OpenIddict.Client.csproj
+++ b/src/OpenIddict.Client/OpenIddict.Client.csproj
@@ -26,6 +26,7 @@ To use the client feature on ASP.NET Core or OWIN/Katana, reference the OpenIddi
   <ItemGroup Condition=" '$(TargetFrameworkIdentifier)' == '.NETFramework' ">
     <PackageReference Include="BouncyCastle.Cryptography" />
     <PackageReference Include="Microsoft.Bcl.Cryptography" />
+    <PackageReference Include="Microsoft.Bcl.Memory" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/src/OpenIddict.Client/OpenIddictClientConfiguration.cs b/src/OpenIddict.Client/OpenIddictClientConfiguration.cs
index 664b3fec..0d5e9a66 100644
--- a/src/OpenIddict.Client/OpenIddictClientConfiguration.cs
+++ b/src/OpenIddict.Client/OpenIddictClientConfiguration.cs
@@ -4,11 +4,11 @@
  * the license and the contributors participating to this project.
  */
 
+using System.Buffers.Text;
 using System.ComponentModel;
 using System.Diagnostics;
 using System.Runtime.CompilerServices;
 using System.Security.Cryptography;
-using System.Security.Cryptography.X509Certificates;
 using System.Text;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Options;
@@ -178,14 +178,14 @@ public sealed class OpenIddictClientConfiguration : IPostConfigureOptions<OpenId
                 Debug.Assert(parameters.Q.X is not null, SR.GetResourceString(SR.ID4004));
 
                 // Only use the 40 first chars of the base64url-encoded X coordinate.
-                var identifier = Base64UrlEncoder.Encode(parameters.Q.X);
+                var identifier = Base64Url.EncodeToString(parameters.Q.X);
                 return identifier[.. Math.Min(identifier.Length, 40)].ToUpperInvariant();
             }
 
             static string GetMLDsaSecurityKeyIdentifier(MlDsaSecurityKey key)
             {
                 // Only use the 40 first chars of the base64url-encoded SHA256 of the ML-DSA public key.
-                var identifier = Base64UrlEncoder.Encode(SHA256.HashData(key.MLDsa.ExportMLDsaPublicKey()));
+                var identifier = Base64Url.EncodeToString(SHA256.HashData(key.MLDsa.ExportMLDsaPublicKey()));
                 return identifier[.. Math.Min(identifier.Length, 40)].ToUpperInvariant();
             }
 
@@ -202,7 +202,7 @@ public sealed class OpenIddictClientConfiguration : IPostConfigureOptions<OpenId
                 }
 
                 // Only use the 40 first chars of the base64url-encoded modulus.
-                var identifier = Base64UrlEncoder.Encode(parameters.Modulus);
+                var identifier = Base64Url.EncodeToString(parameters.Modulus);
                 return identifier[.. Math.Min(identifier.Length, 40)].ToUpperInvariant();
             }
         }
@@ -222,7 +222,7 @@ public sealed class OpenIddictClientConfiguration : IPostConfigureOptions<OpenId
 
             algorithm.TransformFinalBlock([], 0, 0);
 
-            return Base64UrlEncoder.Encode(algorithm.Hash);
+            return Base64Url.EncodeToString(algorithm.Hash);
 
             [MethodImpl(MethodImplOptions.AggressiveInlining)]
             static void TransformBlock(HashAlgorithm algorithm, string input)
diff --git a/src/OpenIddict.Client/OpenIddictClientHandlers.Protection.cs b/src/OpenIddict.Client/OpenIddictClientHandlers.Protection.cs
index 648a44b6..fe84862e 100644
--- a/src/OpenIddict.Client/OpenIddictClientHandlers.Protection.cs
+++ b/src/OpenIddict.Client/OpenIddictClientHandlers.Protection.cs
@@ -4,6 +4,7 @@
  * the license and the contributors participating to this project.
  */
 
+using System.Buffers.Text;
 using System.Collections.Immutable;
 using System.Diagnostics;
 using System.Globalization;
@@ -1183,7 +1184,7 @@ public static partial class OpenIddictClientHandlers
 
                 if (context.IsReferenceToken)
                 {
-                    descriptor.ReferenceId = Base64UrlEncoder.Encode(RandomNumberGenerator.GetBytes(count: 256 / 8));
+                    descriptor.ReferenceId = Base64Url.EncodeToString(RandomNumberGenerator.GetBytes(count: 256 / 8));
                 }
 
                 await _tokenManager.UpdateAsync(token, descriptor);
diff --git a/src/OpenIddict.Client/OpenIddictClientHandlers.cs b/src/OpenIddict.Client/OpenIddictClientHandlers.cs
index c83de599..3782ab7a 100644
--- a/src/OpenIddict.Client/OpenIddictClientHandlers.cs
+++ b/src/OpenIddict.Client/OpenIddictClientHandlers.cs
@@ -19,6 +19,7 @@ using Microsoft.IdentityModel.JsonWebTokens;
 using Microsoft.IdentityModel.Tokens;
 using static OpenIddict.Abstractions.OpenIddictExceptions;
 using System.Runtime.CompilerServices;
+using System.Buffers.Text;
 
 #if !NET
 using Org.BouncyCastle.Crypto.Digests;
@@ -1942,7 +1943,7 @@ public static partial class OpenIddictClientHandlers
                 case { FrontchannelIdentityTokenNonce: string left, StateTokenNonce: string right } when
                     !CryptographicOperations.FixedTimeEquals(
                         left:  MemoryMarshal.AsBytes(left.AsSpan()), // The nonce in the identity token is already hashed.
-                        right: MemoryMarshal.AsBytes(Base64UrlEncoder.Encode(
+                        right: MemoryMarshal.AsBytes(Base64Url.EncodeToString(
                             SHA256.HashData(Encoding.UTF8.GetBytes(right))).AsSpan())):
                     context.Logger.LogWarning(6210, SR.GetResourceString(SR.ID6210));
 
@@ -2072,7 +2073,7 @@ public static partial class OpenIddictClientHandlers
 
                 // Warning: only the left-most half of the access token and authorization code digest is used.
                 // See http://openid.net/specs/openid-connect-core-1_0.html#CodeIDToken for more information.
-                return Base64UrlEncoder.Encode(hash, 0, hash.Length / 2).AsSpan();
+                return Base64Url.EncodeToString(hash.AsSpan(0, hash.Length / 2)).AsSpan();
             }
 
             [MethodImpl(MethodImplOptions.AggressiveInlining)]
@@ -3678,7 +3679,7 @@ public static partial class OpenIddictClientHandlers
                 case { BackchannelIdentityTokenNonce: string left, StateTokenNonce: string right } when
                     !CryptographicOperations.FixedTimeEquals(
                         left:  MemoryMarshal.AsBytes(left.AsSpan()), // The nonce in the identity token is already hashed.
-                        right: MemoryMarshal.AsBytes(Base64UrlEncoder.Encode(
+                        right: MemoryMarshal.AsBytes(Base64Url.EncodeToString(
                             SHA256.HashData(Encoding.UTF8.GetBytes(right))).AsSpan())):
                     context.Logger.LogWarning(6211, SR.GetResourceString(SR.ID6211));
 
@@ -3772,7 +3773,7 @@ public static partial class OpenIddictClientHandlers
 
                 // Warning: only the left-most half of the access token and authorization code digest is used.
                 // See http://openid.net/specs/openid-connect-core-1_0.html#CodeIDToken for more information.
-                return Base64UrlEncoder.Encode(hash, 0, hash.Length / 2).AsSpan();
+                return Base64Url.EncodeToString(hash.AsSpan(0, hash.Length / 2)).AsSpan();
             }
 
             [MethodImpl(MethodImplOptions.AggressiveInlining)]
@@ -5481,7 +5482,7 @@ public static partial class OpenIddictClientHandlers
 
             // Generate a new crypto-secure random identifier that will
             // be used as the non-guessable part of the state token.
-            context.RequestForgeryProtection = Base64UrlEncoder.Encode(
+            context.RequestForgeryProtection = Base64Url.EncodeToString(
                 RandomNumberGenerator.GetBytes(count: 256 / 8));
 
             return ValueTask.CompletedTask;
@@ -5519,7 +5520,7 @@ public static partial class OpenIddictClientHandlers
             // attached to the authorization request so that the identity provider can bind
             // the issued identity tokens to the generated value, which helps detect token
             // replays (and authorization code injection attacks when PKCE is not available).
-            context.Nonce = Base64UrlEncoder.Encode(RandomNumberGenerator.GetBytes(count: 256 / 8));
+            context.Nonce = Base64Url.EncodeToString(RandomNumberGenerator.GetBytes(count: 256 / 8));
 
             return ValueTask.CompletedTask;
         }
@@ -5598,7 +5599,7 @@ public static partial class OpenIddictClientHandlers
             }
 
             // Generate a new crypto-secure random identifier that will be used as the code challenge.
-            context.CodeVerifier = Base64UrlEncoder.Encode(RandomNumberGenerator.GetBytes(count: 256 / 8));
+            context.CodeVerifier = Base64Url.EncodeToString(RandomNumberGenerator.GetBytes(count: 256 / 8));
 
             context.CodeChallenge = context.CodeChallengeMethod switch
             {
@@ -5609,7 +5610,7 @@ public static partial class OpenIddictClientHandlers
                 //
                 // Note: ASCII is deliberately used here, as it's the encoding required by the specification.
                 // For more information, see https://datatracker.ietf.org/doc/html/rfc7636#section-4.2.
-                CodeChallengeMethods.Sha256 => Base64UrlEncoder.Encode(
+                CodeChallengeMethods.Sha256 => Base64Url.EncodeToString(
                     SHA256.HashData(Encoding.ASCII.GetBytes(context.CodeVerifier))),
 
                 _ => throw new InvalidOperationException(SR.GetResourceString(SR.ID0045))
@@ -5921,7 +5922,7 @@ public static partial class OpenIddictClientHandlers
                 context.ResponseType?.Split(Separators.Space) is IList<string> types &&
                 (types.Contains(ResponseTypes.Code) || types.Contains(ResponseTypes.IdToken)))
             {
-                context.Request.Nonce = Base64UrlEncoder.Encode(
+                context.Request.Nonce = Base64Url.EncodeToString(
                     SHA256.HashData(Encoding.UTF8.GetBytes(context.Nonce)));
             }
 
@@ -9180,7 +9181,7 @@ public static partial class OpenIddictClientHandlers
 
             // Generate a new crypto-secure random identifier that will
             // be used as the non-guessable part of the state token.
-            context.RequestForgeryProtection = Base64UrlEncoder.Encode(
+            context.RequestForgeryProtection = Base64Url.EncodeToString(
                 RandomNumberGenerator.GetBytes(count: 256 / 8));
 
             return ValueTask.CompletedTask;
@@ -9207,7 +9208,7 @@ public static partial class OpenIddictClientHandlers
             ArgumentNullException.ThrowIfNull(context);
 
             // Generate a new crypto-secure random identifier that will be used as the nonce.
-            context.Nonce = Base64UrlEncoder.Encode(RandomNumberGenerator.GetBytes(count: 256 / 8));
+            context.Nonce = Base64Url.EncodeToString(RandomNumberGenerator.GetBytes(count: 256 / 8));
 
             return ValueTask.CompletedTask;
         }
diff --git a/src/OpenIddict.Server.DataProtection/OpenIddictServerDataProtectionHandlers.Protection.cs b/src/OpenIddict.Server.DataProtection/OpenIddictServerDataProtectionHandlers.Protection.cs
index 2d78e6a7..7923a83a 100644
--- a/src/OpenIddict.Server.DataProtection/OpenIddictServerDataProtectionHandlers.Protection.cs
+++ b/src/OpenIddict.Server.DataProtection/OpenIddictServerDataProtectionHandlers.Protection.cs
@@ -4,12 +4,12 @@
  * the license and the contributors participating to this project.
  */
 
+using System.Buffers.Text;
 using System.Collections.Immutable;
 using System.Security.Claims;
 using Microsoft.AspNetCore.DataProtection;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
-using Microsoft.IdentityModel.Tokens;
 using static OpenIddict.Server.DataProtection.OpenIddictServerDataProtectionConstants.Purposes;
 using static OpenIddict.Server.OpenIddictServerHandlers.Protection;
 using Schemes = OpenIddict.Server.DataProtection.OpenIddictServerDataProtectionConstants.Purposes.Schemes;
@@ -229,7 +229,7 @@ public static partial class OpenIddictServerDataProtectionHandlers
 
                     try
                     {
-                        using var buffer = new MemoryStream(protector.Unprotect(Base64UrlEncoder.DecodeBytes(context.Token)));
+                        using var buffer = new MemoryStream(protector.Unprotect(Base64Url.DecodeFromChars(context.Token)));
                         using var reader = new BinaryReader(buffer);
 
                         // Note: since the data format relies on a data protector using different "purposes" strings
@@ -382,7 +382,7 @@ public static partial class OpenIddictServerDataProtectionHandlers
 
                 _options.CurrentValue.Formatter.WriteToken(writer, context.Principal);
 
-                context.Token = Base64UrlEncoder.Encode(protector.Protect(buffer.ToArray()));
+                context.Token = Base64Url.EncodeToString(protector.Protect(buffer.ToArray()));
 
                 context.Logger.LogTrace(6016, SR.GetResourceString(SR.ID6016), context.TokenType,
                     context.Token, context.Principal.Claims);
diff --git a/src/OpenIddict.Server/OpenIddict.Server.csproj b/src/OpenIddict.Server/OpenIddict.Server.csproj
index 0566a426..12cf0c52 100644
--- a/src/OpenIddict.Server/OpenIddict.Server.csproj
+++ b/src/OpenIddict.Server/OpenIddict.Server.csproj
@@ -24,6 +24,7 @@ To use the server feature on ASP.NET Core or OWIN/Katana, reference the OpenIddi
   <ItemGroup Condition=" '$(TargetFrameworkIdentifier)' == '.NETFramework' ">
     <PackageReference Include="BouncyCastle.Cryptography" />
     <PackageReference Include="Microsoft.Bcl.Cryptography" />
+    <PackageReference Include="Microsoft.Bcl.Memory" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/src/OpenIddict.Server/OpenIddictServerConfiguration.cs b/src/OpenIddict.Server/OpenIddictServerConfiguration.cs
index b11d82b7..4930ac04 100644
--- a/src/OpenIddict.Server/OpenIddictServerConfiguration.cs
+++ b/src/OpenIddict.Server/OpenIddictServerConfiguration.cs
@@ -4,6 +4,7 @@
  * the license and the contributors participating to this project.
  */
 
+using System.Buffers.Text;
 using System.ComponentModel;
 using System.Diagnostics;
 using System.Globalization;
@@ -141,14 +142,14 @@ public sealed class OpenIddictServerConfiguration : IPostConfigureOptions<OpenId
                 Debug.Assert(parameters.Q.X is not null, SR.GetResourceString(SR.ID4004));
 
                 // Only use the 40 first chars of the base64url-encoded X coordinate.
-                var identifier = Base64UrlEncoder.Encode(parameters.Q.X);
+                var identifier = Base64Url.EncodeToString(parameters.Q.X);
                 return identifier[.. Math.Min(identifier.Length, 40)].ToUpperInvariant();
             }
 
             static string GetMLDsaSecurityKeyIdentifier(MlDsaSecurityKey key)
             {
                 // Only use the 40 first chars of the base64url-encoded SHA256 of the ML-DSA public key.
-                var identifier = Base64UrlEncoder.Encode(SHA256.HashData(key.MLDsa.ExportMLDsaPublicKey()));
+                var identifier = Base64Url.EncodeToString(SHA256.HashData(key.MLDsa.ExportMLDsaPublicKey()));
                 return identifier[.. Math.Min(identifier.Length, 40)].ToUpperInvariant();
             }
 
@@ -165,7 +166,7 @@ public sealed class OpenIddictServerConfiguration : IPostConfigureOptions<OpenId
                 }
 
                 // Only use the 40 first chars of the base64url-encoded modulus.
-                var identifier = Base64UrlEncoder.Encode(parameters.Modulus);
+                var identifier = Base64Url.EncodeToString(parameters.Modulus);
                 return identifier[.. Math.Min(identifier.Length, 40)].ToUpperInvariant();
             }
         }
diff --git a/src/OpenIddict.Server/OpenIddictServerHandlers.Discovery.cs b/src/OpenIddict.Server/OpenIddictServerHandlers.Discovery.cs
index 368d85cb..0992a38b 100644
--- a/src/OpenIddict.Server/OpenIddictServerHandlers.Discovery.cs
+++ b/src/OpenIddict.Server/OpenIddictServerHandlers.Discovery.cs
@@ -4,6 +4,7 @@
  * the license and the contributors participating to this project.
  */
 
+using System.Buffers.Text;
 using System.Collections.Immutable;
 using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
@@ -1290,8 +1291,8 @@ public static partial class OpenIddictServerHandlers
 
                         // Note: both X and Y must be base64url-encoded.
                         // See https://tools.ietf.org/html/rfc7518#section-6.2.1.2.
-                        key.X = Base64UrlEncoder.Encode(parameters.Q.X);
-                        key.Y = Base64UrlEncoder.Encode(parameters.Q.Y);
+                        key.X = Base64Url.EncodeToString(parameters.Q.X);
+                        key.Y = Base64Url.EncodeToString(parameters.Q.Y);
                     }
 
                     // Note: while ML-DSA is supported on .NET Framework via the Microsoft.Bcl.Cryptography package, SHAKE256 - used
@@ -1310,7 +1311,7 @@ public static partial class OpenIddictServerHandlers
                         }
 
                         key.Kty = JsonWebAlgorithmsKeyTypes.Akp;
-                        key.Pub = Base64UrlEncoder.Encode(blob);
+                        key.Pub = Base64Url.EncodeToString(blob);
                     }
 
                     else if (credentials.Key.IsSupportedAlgorithm(SecurityAlgorithms.RsaSha256) ||
@@ -1329,8 +1330,8 @@ public static partial class OpenIddictServerHandlers
 
                         // Note: both E and N must be base64url-encoded.
                         // See https://tools.ietf.org/html/rfc7518#section-6.3.1.1.
-                        key.E = Base64UrlEncoder.Encode(parameters.Exponent);
-                        key.N = Base64UrlEncoder.Encode(parameters.Modulus);
+                        key.E = Base64Url.EncodeToString(parameters.Exponent);
+                        key.N = Base64Url.EncodeToString(parameters.Modulus);
                     }
 
                     // If the signing key is embedded in a X.509 certificate, set
@@ -1339,11 +1340,11 @@ public static partial class OpenIddictServerHandlers
                     {
                         // x5t must be base64url-encoded.
                         // See https://tools.ietf.org/html/rfc7517#section-4.8.
-                        key.X5t = Base64UrlEncoder.Encode(certificate.GetCertHash());
+                        key.X5t = Base64Url.EncodeToString(certificate.GetCertHash());
 
                         // x5t#S256 must be base64url-encoded.
                         // See https://tools.ietf.org/html/rfc7517#section-4.9.
-                        key.X5tS256 = Base64UrlEncoder.Encode(certificate.GetCertHash(HashAlgorithmName.SHA256));
+                        key.X5tS256 = Base64Url.EncodeToString(certificate.GetCertHash(HashAlgorithmName.SHA256));
 
                         // Unlike E or N, the certificates contained in x5c
                         // must be base64-encoded and not base64url-encoded.
diff --git a/src/OpenIddict.Server/OpenIddictServerHandlers.Exchange.cs b/src/OpenIddict.Server/OpenIddictServerHandlers.Exchange.cs
index 8d9b400f..bc3c466c 100644
--- a/src/OpenIddict.Server/OpenIddictServerHandlers.Exchange.cs
+++ b/src/OpenIddict.Server/OpenIddictServerHandlers.Exchange.cs
@@ -4,6 +4,7 @@
  * the license and the contributors participating to this project.
  */
 
+using System.Buffers.Text;
 using System.Collections.Immutable;
 using System.Diagnostics;
 using System.Runtime.InteropServices;
@@ -13,7 +14,6 @@ using System.Text;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
-using Microsoft.IdentityModel.Tokens;
 
 namespace OpenIddict.Server;
 
@@ -1993,7 +1993,7 @@ public static partial class OpenIddictServerHandlers
                     // In this case, the raw bytes of the verifier are directly compared to the challenge.
                     CodeChallengeMethods.Plain => context.Request.CodeVerifier,
 
-                    CodeChallengeMethods.Sha256 => Base64UrlEncoder.Encode(
+                    CodeChallengeMethods.Sha256 => Base64Url.EncodeToString(
                         SHA256.HashData(Encoding.ASCII.GetBytes(context.Request.CodeVerifier))),
 
                     null or { Length: 0 } => throw new InvalidOperationException(SR.GetResourceString(SR.ID0268)),
diff --git a/src/OpenIddict.Server/OpenIddictServerHandlers.Protection.cs b/src/OpenIddict.Server/OpenIddictServerHandlers.Protection.cs
index 7398f7a2..6ba9cb42 100644
--- a/src/OpenIddict.Server/OpenIddictServerHandlers.Protection.cs
+++ b/src/OpenIddict.Server/OpenIddictServerHandlers.Protection.cs
@@ -4,6 +4,7 @@
  * the license and the contributors participating to this project.
  */
 
+using System.Buffers.Text;
 using System.Collections.Immutable;
 using System.Diagnostics;
 using System.Globalization;
@@ -1179,7 +1180,7 @@ public static partial class OpenIddictServerHandlers
 
                     // If the thumbprint of the certificate doesn't match the hash
                     // resolved from the confirmation claim, return an error.
-                    var hash = Base64UrlEncoder.Encode(certificate.GetCertHash(HashAlgorithmName.SHA256));
+                    var hash = Base64Url.EncodeToString(certificate.GetCertHash(HashAlgorithmName.SHA256));
                     if (!CryptographicOperations.FixedTimeEquals(
                         left : MemoryMarshal.AsBytes<char>(hash),
                         right: MemoryMarshal.AsBytes<char>(thumbprint)))
@@ -1844,7 +1845,7 @@ public static partial class OpenIddictServerHandlers
                     else
                     {
                         // For other tokens, generate a base64url-encoded 256-bit random identifier.
-                        descriptor.ReferenceId = Base64UrlEncoder.Encode(RandomNumberGenerator.GetBytes(count: 256 / 8));
+                        descriptor.ReferenceId = Base64Url.EncodeToString(RandomNumberGenerator.GetBytes(count: 256 / 8));
                     }
                 }
 
diff --git a/src/OpenIddict.Server/OpenIddictServerHandlers.cs b/src/OpenIddict.Server/OpenIddictServerHandlers.cs
index b97512b4..29765677 100644
--- a/src/OpenIddict.Server/OpenIddictServerHandlers.cs
+++ b/src/OpenIddict.Server/OpenIddictServerHandlers.cs
@@ -4,6 +4,7 @@
  * the license and the contributors participating to this project.
  */
 
+using System.Buffers.Text;
 using System.Collections.Immutable;
 using System.ComponentModel;
 using System.Diagnostics;
@@ -3667,7 +3668,7 @@ public static partial class OpenIddictServerHandlers
 
             static JsonNode CreateConfirmationClaim(X509Certificate2 certificate) => new JsonObject
             {
-                [JsonWebKeyParameterNames.X5tS256] = Base64UrlEncoder.Encode(certificate.GetCertHash(HashAlgorithmName.SHA256))
+                [JsonWebKeyParameterNames.X5tS256] = Base64Url.EncodeToString(certificate.GetCertHash(HashAlgorithmName.SHA256))
             };
         }
     }
@@ -4196,7 +4197,7 @@ public static partial class OpenIddictServerHandlers
 
             static JsonNode CreateConfirmationClaim(X509Certificate2 certificate) => new JsonObject
             {
-                [JsonWebKeyParameterNames.X5tS256] = Base64UrlEncoder.Encode(certificate.GetCertHash(HashAlgorithmName.SHA256))
+                [JsonWebKeyParameterNames.X5tS256] = Base64Url.EncodeToString(certificate.GetCertHash(HashAlgorithmName.SHA256))
             };
         }
     }
@@ -4489,7 +4490,7 @@ public static partial class OpenIddictServerHandlers
 
             static JsonNode CreateConfirmationClaim(X509Certificate2 certificate) => new JsonObject
             {
-                [JsonWebKeyParameterNames.X5tS256] = Base64UrlEncoder.Encode(certificate.GetCertHash(HashAlgorithmName.SHA256))
+                [JsonWebKeyParameterNames.X5tS256] = Base64Url.EncodeToString(certificate.GetCertHash(HashAlgorithmName.SHA256))
             };
         }
     }
@@ -5316,7 +5317,7 @@ public static partial class OpenIddictServerHandlers
 
                 // Note: only the left-most half of the hash is used.
                 // See http://openid.net/specs/openid-connect-core-1_0.html#CodeIDToken
-                context.IdentityTokenPrincipal.SetClaim(Claims.AccessTokenHash, Base64UrlEncoder.Encode(digest, 0, digest.Length / 2));
+                context.IdentityTokenPrincipal.SetClaim(Claims.AccessTokenHash, Base64Url.EncodeToString(digest.AsSpan(0, digest.Length / 2)));
             }
 
             if (!string.IsNullOrEmpty(context.AuthorizationCode))
@@ -5325,7 +5326,7 @@ public static partial class OpenIddictServerHandlers
 
                 // Note: only the left-most half of the hash is used.
                 // See http://openid.net/specs/openid-connect-core-1_0.html#HybridIDToken
-                context.IdentityTokenPrincipal.SetClaim(Claims.CodeHash, Base64UrlEncoder.Encode(digest, 0, digest.Length / 2));
+                context.IdentityTokenPrincipal.SetClaim(Claims.CodeHash, Base64Url.EncodeToString(digest.AsSpan(0, digest.Length / 2)));
             }
 
             return ValueTask.CompletedTask;
diff --git a/src/OpenIddict.Validation.DataProtection/OpenIddictValidationDataProtectionHandlers.Protection.cs b/src/OpenIddict.Validation.DataProtection/OpenIddictValidationDataProtectionHandlers.Protection.cs
index 1cc8cac9..e3d8d3b2 100644
--- a/src/OpenIddict.Validation.DataProtection/OpenIddictValidationDataProtectionHandlers.Protection.cs
+++ b/src/OpenIddict.Validation.DataProtection/OpenIddictValidationDataProtectionHandlers.Protection.cs
@@ -4,12 +4,12 @@
  * the license and the contributors participating to this project.
  */
 
+using System.Buffers.Text;
 using System.Collections.Immutable;
 using System.Security.Claims;
 using Microsoft.AspNetCore.DataProtection;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
-using Microsoft.IdentityModel.Tokens;
 using static OpenIddict.Validation.DataProtection.OpenIddictValidationDataProtectionConstants.Purposes;
 using static OpenIddict.Validation.OpenIddictValidationHandlers.Protection;
 using Schemes = OpenIddict.Validation.DataProtection.OpenIddictValidationDataProtectionConstants.Purposes.Schemes;
@@ -127,7 +127,7 @@ public static partial class OpenIddictValidationDataProtectionHandlers
 
                     try
                     {
-                        using var buffer = new MemoryStream(protector.Unprotect(Base64UrlEncoder.DecodeBytes(context.Token)));
+                        using var buffer = new MemoryStream(protector.Unprotect(Base64Url.DecodeFromChars(context.Token)));
                         using var reader = new BinaryReader(buffer);
 
                         // Note: since the data format relies on a data protector using different "purposes" strings
diff --git a/src/OpenIddict.Validation.SystemNetHttp/OpenIddictValidationSystemNetHttpContext.cs b/src/OpenIddict.Validation.SystemNetHttp/OpenIddictValidationSystemNetHttpContext.cs
index 25906d18..6f1f3954 100644
--- a/src/OpenIddict.Validation.SystemNetHttp/OpenIddictValidationSystemNetHttpContext.cs
+++ b/src/OpenIddict.Validation.SystemNetHttp/OpenIddictValidationSystemNetHttpContext.cs
@@ -4,10 +4,10 @@
  * the license and the contributors participating to this project.
  */
 
+using System.Buffers.Text;
 using System.ComponentModel;
 using System.Security.Cryptography;
 using System.Security.Cryptography.X509Certificates;
-using Microsoft.IdentityModel.Tokens;
 
 namespace OpenIddict.Validation.SystemNetHttp;
 
@@ -52,6 +52,6 @@ public sealed class OpenIddictValidationSystemNetHttpContext
 
         algorithm.TransformFinalBlock([], 0, 0);
 
-        return Base64UrlEncoder.Encode(algorithm.Hash);
+        return Base64Url.EncodeToString(algorithm.Hash);
     }
 }
diff --git a/src/OpenIddict.Validation/OpenIddict.Validation.csproj b/src/OpenIddict.Validation/OpenIddict.Validation.csproj
index eb5469ca..6f475b77 100644
--- a/src/OpenIddict.Validation/OpenIddict.Validation.csproj
+++ b/src/OpenIddict.Validation/OpenIddict.Validation.csproj
@@ -24,6 +24,7 @@ To use the validation feature on ASP.NET Core or OWIN/Katana, reference the Open
 
   <ItemGroup Condition=" '$(TargetFrameworkIdentifier)' == '.NETFramework' ">
     <PackageReference Include="Microsoft.Bcl.Cryptography" />
+    <PackageReference Include="Microsoft.Bcl.Memory" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/src/OpenIddict.Validation/OpenIddictValidationHandlers.Protection.cs b/src/OpenIddict.Validation/OpenIddictValidationHandlers.Protection.cs
index b1753420..a2bc7523 100644
--- a/src/OpenIddict.Validation/OpenIddictValidationHandlers.Protection.cs
+++ b/src/OpenIddict.Validation/OpenIddictValidationHandlers.Protection.cs
@@ -4,6 +4,7 @@
  * the license and the contributors participating to this project.
  */
 
+using System.Buffers.Text;
 using System.Collections.Immutable;
 using System.Diagnostics;
 using System.Globalization;
@@ -866,7 +867,7 @@ public static partial class OpenIddictValidationHandlers
 
                     // If the thumbprint of the certificate doesn't match the hash
                     // resolved from the confirmation claim, return an error.
-                    var hash = Base64UrlEncoder.Encode(certificate.GetCertHash(HashAlgorithmName.SHA256));
+                    var hash = Base64Url.EncodeToString(certificate.GetCertHash(HashAlgorithmName.SHA256));
                     if (!CryptographicOperations.FixedTimeEquals(
                         left : MemoryMarshal.AsBytes<char>(hash),
                         right: MemoryMarshal.AsBytes<char>(thumbprint)))
diff --git a/src/OpenIddict.Validation/OpenIddictValidationHandlers.cs b/src/OpenIddict.Validation/OpenIddictValidationHandlers.cs
index d094de36..6484c875 100644
--- a/src/OpenIddict.Validation/OpenIddictValidationHandlers.cs
+++ b/src/OpenIddict.Validation/OpenIddictValidationHandlers.cs
@@ -4,6 +4,7 @@
  * the license and the contributors participating to this project.
  */
 
+using System.Buffers.Text;
 using System.Collections.Immutable;
 using System.ComponentModel;
 using System.Diagnostics;
@@ -921,7 +922,7 @@ public static partial class OpenIddictValidationHandlers
 
                 // If the thumbprint of the certificate doesn't match the hash
                 // resolved from the confirmation claim, return an error.
-                var hash = Base64UrlEncoder.Encode(certificate.GetCertHash(HashAlgorithmName.SHA256));
+                var hash = Base64Url.EncodeToString(certificate.GetCertHash(HashAlgorithmName.SHA256));
                 if (!CryptographicOperations.FixedTimeEquals(
                     left : MemoryMarshal.AsBytes<char>(hash),
                     right: MemoryMarshal.AsBytes<char>(thumbprint)))
diff --git a/test/OpenIddict.Client.Tests/OpenIddictClientConfigurationTests.cs b/test/OpenIddict.Client.Tests/OpenIddictClientConfigurationTests.cs
index 99a993f6..8af5e6c4 100644
--- a/test/OpenIddict.Client.Tests/OpenIddictClientConfigurationTests.cs
+++ b/test/OpenIddict.Client.Tests/OpenIddictClientConfigurationTests.cs
@@ -1,6 +1,5 @@
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.IdentityModel.Protocols;
-using Microsoft.IdentityModel.Tokens;
 using Moq;
 using Xunit;
 
diff --git a/test/OpenIddict.Core.Tests/Managers/OpenIddictApplicationManagerTests.cs b/test/OpenIddict.Core.Tests/Managers/OpenIddictApplicationManagerTests.cs
index b5e5b9bd..8e014b64 100644
--- a/test/OpenIddict.Core.Tests/Managers/OpenIddictApplicationManagerTests.cs
+++ b/test/OpenIddict.Core.Tests/Managers/OpenIddictApplicationManagerTests.cs
@@ -5,7 +5,6 @@
  */
 
 using System.Buffers.Binary;
-using System.Collections.Immutable;
 using System.ComponentModel.DataAnnotations;
 using System.Globalization;
 using System.Security.Cryptography;
diff --git a/test/OpenIddict.Server.IntegrationTests/OpenIddictServerIntegrationTests.Discovery.cs b/test/OpenIddict.Server.IntegrationTests/OpenIddictServerIntegrationTests.Discovery.cs
index b2f487e5..f0bb1f9b 100644
--- a/test/OpenIddict.Server.IntegrationTests/OpenIddictServerIntegrationTests.Discovery.cs
+++ b/test/OpenIddict.Server.IntegrationTests/OpenIddictServerIntegrationTests.Discovery.cs
@@ -4,6 +4,7 @@
  * the license and the contributors participating to this project.
  */
 
+using System.Buffers.Text;
 using System.Collections.Immutable;
 using System.Net.Http;
 using System.Security.Cryptography;
@@ -1486,8 +1487,8 @@ public abstract partial class OpenIddictServerIntegrationTests
         Assert.Null(key?[JsonWebKeyParameterNames.P]);
         Assert.Null(key?[JsonWebKeyParameterNames.Q]);
 
-        Assert.Equal(parameters.Exponent, Base64UrlEncoder.DecodeBytes((string?) key?[JsonWebKeyParameterNames.E]));
-        Assert.Equal(parameters.Modulus, Base64UrlEncoder.DecodeBytes((string?) key?[JsonWebKeyParameterNames.N]));
+        Assert.Equal(parameters.Exponent, Base64Url.DecodeFromChars((string?) key?[JsonWebKeyParameterNames.E]));
+        Assert.Equal(parameters.Modulus, Base64Url.DecodeFromChars((string?) key?[JsonWebKeyParameterNames.N]));
     }
 
     [Theory]
@@ -1537,8 +1538,8 @@ public abstract partial class OpenIddictServerIntegrationTests
         // Assert
         Assert.Null(key?[JsonWebKeyParameterNames.D]);
 
-        Assert.Equal(parameters.Q.X, Base64UrlEncoder.DecodeBytes((string?) key?[JsonWebKeyParameterNames.X]));
-        Assert.Equal(parameters.Q.Y, Base64UrlEncoder.DecodeBytes((string?) key?[JsonWebKeyParameterNames.Y]));
+        Assert.Equal(parameters.Q.X, Base64Url.DecodeFromChars((string?) key?[JsonWebKeyParameterNames.X]));
+        Assert.Equal(parameters.Q.Y, Base64Url.DecodeFromChars((string?) key?[JsonWebKeyParameterNames.Y]));
     }
 
     [SkippableFact(typeof(PlatformNotSupportedException))]
@@ -1563,7 +1564,7 @@ public abstract partial class OpenIddictServerIntegrationTests
         // Assert
         Assert.Equal(JsonWebAlgorithmsKeyTypes.Akp, (string?) key?[JsonWebKeyParameterNames.Kty]);
         Assert.Equal(SecurityAlgorithms.MlDsa44, (string?) key?[JsonWebKeyParameterNames.Alg]);
-        Assert.Equal(blob, Base64UrlEncoder.DecodeBytes((string?) key?[JsonWebKeyParameterNames.Pub]));
+        Assert.Equal(blob, Base64Url.DecodeFromChars((string?) key?[JsonWebKeyParameterNames.Pub]));
     }
 
     [Fact]
diff --git a/test/OpenIddict.Validation.Tests/OpenIddictValidationBuilderTests.cs b/test/OpenIddict.Validation.Tests/OpenIddictValidationBuilderTests.cs
index 9409fbc5..09dfbec7 100644
--- a/test/OpenIddict.Validation.Tests/OpenIddictValidationBuilderTests.cs
+++ b/test/OpenIddict.Validation.Tests/OpenIddictValidationBuilderTests.cs
@@ -6,7 +6,6 @@ using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Options;
 using Microsoft.IdentityModel.Tokens;
 using Moq;
-using OpenIddict.Abstractions;
 using Xunit;
 using static OpenIddict.Validation.OpenIddictValidationEvents;