diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 66f921b..6e8fa72 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -14,8 +14,6 @@ jobs:
     permissions:
       contents: read
       packages: write
-      id-token: write
-      attestations: write
 
     env:
       GRADLE_OPTS: -Dorg.gradle.caching=true
@@ -30,7 +28,9 @@ jobs:
           java-version: 21
       - uses: gradle/actions/setup-gradle@v4
       - name: Release maven artifacts
-        run: ./gradlew -Pversion=$version publish uploadSignaturesToGitHub
+        run: ./gradlew -Pversion=$version publish
         env:
           ORG_GRADLE_PROJECT_GitHubPackagesUsername: ${{ github.actor }}
           ORG_GRADLE_PROJECT_GitHubPackagesPassword: ${{ github.token }}
+          ORG_GRADLE_PROJECT_signingKey: ${{ secrets.SIGNING_PRIVATE_KEY }}
+          ORG_GRADLE_PROJECT_signingPassword: ${{ secrets.SIGNING_PASSWORD }}
diff --git a/gradle.properties b/gradle.properties
index 07f3142..513e23f 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -4,5 +4,5 @@ org.gradle.parallel=true
 org.gradle.jvmargs=-Xmx2048m
 org.gradle.configuration-cache=true
 org.gradle.configureondemand=true
-org.gradle.unsafe.isolated-projects=false
+org.gradle.unsafe.isolated-projects=true
 group=io.github.hfhbd.adventofcode
diff --git a/gradle/build-logic/build.gradle.kts b/gradle/build-logic/build.gradle.kts
index ad19c6d..375fed2 100644
--- a/gradle/build-logic/build.gradle.kts
+++ b/gradle/build-logic/build.gradle.kts
@@ -4,9 +4,6 @@ plugins {
 
 dependencies {
     implementation(libs.plugins.kotlin.jvm.dep)
-    implementation(libs.plugins.sigstore.dep)
-    implementation(libs.ktor.client.cio)
-    implementation(libs.ktor.client.logging)
 }
 
 val Provider<PluginDependency>.dep: Provider<String> get() = map { "${it.pluginId}:${it.pluginId}.gradle.plugin:${it.version}" }
diff --git a/gradle/build-logic/settings.gradle.kts b/gradle/build-logic/settings.gradle.kts
index fe24033..99a9a62 100644
--- a/gradle/build-logic/settings.gradle.kts
+++ b/gradle/build-logic/settings.gradle.kts
@@ -2,7 +2,6 @@ dependencyResolutionManagement {
     repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)
     repositories {
         mavenCentral()
-        gradlePluginPortal()
     }
     versionCatalogs.register("libs") {
         from(files("../libs.versions.toml"))
diff --git a/gradle/build-logic/src/main/kotlin/UploadSignatures.kt b/gradle/build-logic/src/main/kotlin/UploadSignatures.kt
deleted file mode 100644
index 4944553..0000000
--- a/gradle/build-logic/src/main/kotlin/UploadSignatures.kt
+++ /dev/null
@@ -1,62 +0,0 @@
-import io.ktor.client.*
-import io.ktor.client.engine.cio.*
-import io.ktor.client.plugins.*
-import io.ktor.client.plugins.logging.LogLevel
-import io.ktor.client.plugins.logging.Logger
-import io.ktor.client.plugins.logging.Logging
-import io.ktor.client.request.*
-import io.ktor.http.*
-import kotlinx.coroutines.runBlocking
-import org.gradle.api.DefaultTask
-import org.gradle.api.credentials.PasswordCredentials
-import org.gradle.api.file.ConfigurableFileCollection
-import org.gradle.api.provider.Property
-import org.gradle.api.tasks.*
-import org.gradle.kotlin.dsl.credentials
-import org.gradle.work.DisableCachingByDefault
-
-@DisableCachingByDefault(because = "Remote operation")
-abstract class UploadSignatures : DefaultTask() {
-    @get:InputFiles
-    @get:PathSensitive(PathSensitivity.NONE)
-    abstract val signatures: ConfigurableFileCollection
-
-    @get:Input
-    abstract val githubApiUrl: Property<String>
-
-    @get:Input
-    val githubCredentials = project.providers.credentials(PasswordCredentials::class, "GitHubPackages")
-
-    @get:Input
-    abstract val githubRepository: Property<String>
-
-
-    @TaskAction
-    internal fun uploadSignatures(): Unit = runBlocking {
-        HttpClient(CIO) {
-            defaultRequest {
-                url.takeFrom(githubApiUrl.get())
-                accept(ContentType.parse("application/vnd.github+json"))
-                bearerAuth(githubCredentials.get().password!!)
-            }
-            expectSuccess = true
-            install(Logging) {
-                logger = object : Logger {
-                    override fun log(message: String) {
-                        this@UploadSignatures.logger.info(message)
-                    }
-                }
-                level = LogLevel.ALL
-            }
-        }.use { client ->
-            for (file in signatures) {
-                client.post(
-                    "/repos/${githubRepository.get()}/attestations"
-                ) {
-                    //language=json
-                    setBody("""{ "bundle": ${file.readText()} }""")
-                }
-            }
-        }
-    }
-}
diff --git a/gradle/build-logic/src/main/kotlin/setup.gradle.kts b/gradle/build-logic/src/main/kotlin/setup.gradle.kts
index 76d7537..5a48ca7 100644
--- a/gradle/build-logic/src/main/kotlin/setup.gradle.kts
+++ b/gradle/build-logic/src/main/kotlin/setup.gradle.kts
@@ -1,10 +1,7 @@
-import dev.sigstore.sign.tasks.SigstoreSignFilesTask
-
 plugins {
     kotlin("jvm")
     id("maven-publish")
     id("signing")
-    id("dev.sigstore.sign")
 }
 
 kotlin.jvmToolchain(8)
@@ -42,21 +39,17 @@ java {
     withSourcesJar()
 }
 
+signing {
+    val signingKey = providers.gradleProperty("signingKey")
+    if (signingKey.isPresent) {
+        useInMemoryPgpKeys(signingKey.get(), providers.gradleProperty("signingPassword").get())
+        sign(publishing.publications)
+    }
+}
+
 tasks.withType<AbstractArchiveTask>().configureEach {
     isPreserveFileTimestamps = false
     isReproducibleFileOrder = true
     filePermissions {}
     dirPermissions {}
 }
-
-tasks.withType(SigstoreSignFilesTask::class).configureEach {
-    launcher.set(javaToolchains.launcherFor {
-        languageVersion.set(JavaLanguageVersion.of(21))
-    })
-}
-
-tasks.register("uploadSignaturesToGitHub", UploadSignatures::class) {
-    signatures.from(tasks.withType(SigstoreSignFilesTask::class))
-    githubApiUrl = providers.environmentVariable("GITHUB_API_URL")
-    githubRepository = providers.environmentVariable("GITHUB_REPOSITORY")
-}
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index f781a70..21cc662 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -1,11 +1,5 @@
 [versions]
 kotlin = "2.1.0-Beta1"
-ktor = "2.3.12"
-
-[libraries]
-ktor-client-cio = { module = "io.ktor:ktor-client-cio", version.ref = "ktor" }
-ktor-client-logging = { module = "io.ktor:ktor-client-logging", version.ref = "ktor" }
 
 [plugins]
 kotlin-jvm = { id = "org.jetbrains.kotlin.jvm", version.ref = "kotlin" }
-sigstore = { id = "dev.sigstore.sign", version = "1.0.0" }