diff --git a/.idea/misc.xml b/.idea/misc.xml
index 775445d..7deb2c1 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -1,7 +1,10 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
   <component name="ExternalStorageConfigurationManager" enabled="true" />
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_17" default="true" project-jdk-name="corretto-17" project-jdk-type="JavaSDK">
+  <component name="FrameworkDetectionExcludesConfiguration">
+    <file type="web" url="file://$PROJECT_DIR$" />
+  </component>
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_21" project-jdk-name="corretto-17" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/out" />
   </component>
 </project>
\ No newline at end of file
diff --git a/README.md b/README.md
index 06bd31e..43ad863 100644
--- a/README.md
+++ b/README.md
@@ -2,6 +2,14 @@
 
 Kotlin Multiplatform cryptographic primitives using modern strong cryptography.
 
+## v0.9.0 for kotlin 2.2.21, new kotlin time compatible
+
+The primary goal was to fix kotlin-caused incompatibilities with kotlinx.datetime.Instant and Clock; the upgrade shoud be in-place 
+replacement providing calling code ises `kotlin.time.Instant` and
+`kotlin.time.Clock` respectively. No other changes are needed.
+
+Also we start to add small syntax sugar methods.
+
 ## v.0.8.4 is built for all platform, IOS and wasmJS included
 
 Cryptographic API works exactly the same and compiles to any platform supported listed below with no change in source code.
diff --git a/build.gradle.kts b/build.gradle.kts
index 1974ccc..5086bc6 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -13,14 +13,14 @@ import org.jetbrains.kotlin.gradle.ExperimentalWasmDsl
 import org.jetbrains.kotlin.gradle.dsl.JvmTarget
 
 plugins {
-    kotlin("multiplatform") version "2.2.20"
-    id("org.jetbrains.kotlin.plugin.serialization") version "2.2.20"
+    kotlin("multiplatform") version "2.2.21"
+    id("org.jetbrains.kotlin.plugin.serialization") version "2.2.21"
     id("org.jetbrains.dokka") version "1.9.20"
     `maven-publish`
 }
 
 group = "net.sergeych"
-version = "0.8.5"
+version = "0.9.0"
 
 repositories {
     mavenCentral()
@@ -31,12 +31,8 @@ repositories {
 }
 
 kotlin {
-    jvm {
-        @OptIn(ExperimentalKotlinGradlePluginApi::class)
-        compilerOptions {
-            jvmTarget = JvmTarget.JVM_11
-        }
-    }
+    jvmToolchain(21)
+    jvm()
     js {
         browser()
         nodejs()
@@ -60,18 +56,20 @@ kotlin {
             languageSettings.optIn("kotlinx.serialization.ExperimentalSerializationApi")
             languageSettings.optIn("kotlinx.coroutines.ExperimentalCoroutinesApi")
             languageSettings.optIn("kotlin.ExperimentalUnsignedTypes")
+            languageSettings.optIn("kotlin.time.ExperimentalTime")
         }
 
         val commonMain by getting {
             dependencies {
-                implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.8.1")
-                implementation("org.jetbrains.kotlinx:kotlinx-serialization-json:1.7.0")
+                implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.10.2")
+                implementation("org.jetbrains.kotlinx:kotlinx-serialization-json:1.9.0")
 
                 implementation("net.sergeych:multiplatform-crypto-libsodium-bindings:0.9.6")
                 implementation(project.dependencies.platform("org.kotlincrypto.hash:bom:0.5.1"))
                 implementation("org.kotlincrypto.hash:sha3")
                 api("com.ionspin.kotlin:bignum:0.3.10")
-                api("net.sergeych:mp_bintools:0.2.2")
+                api("net.sergeych:mp_bintools:0.3.2")
+
             }
         }
         val commonTest by getting {
@@ -114,6 +112,14 @@ publishing {
     }
 }
 
+tasks.named<Test>("jvmTest") {
+    // Ignore Kotlin synthetic classes generated from files that look like tests
+    exclude("**/*TestKt.class")
+    exclude("**/*TestsKt.class")
+    exclude("**/*AssertThrowsKt.class")
+    exclude("**/*Test_toolsKt.class")
+}
+
 tasks.dokkaHtml.configure {
     outputDirectory.set(buildDir.resolve("dokka"))
     dokkaSourceSets {
diff --git a/gradle.properties b/gradle.properties
index 7a7674f..2804048 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -9,3 +9,7 @@
 #
 
 kotlin.code.style=official
+org.gradle.parallel=true
+org.gradle.jvmargs=-Xmx4096M -Dfile.encoding=UTF-8
+org.gradle.configuration-cache=true
+org.gradle.caching=true
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 0e287ab..e5bc481 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -10,6 +10,6 @@
 
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.2-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.14.3-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
\ No newline at end of file
diff --git a/src/commonMain/kotlin/net/sergeych/crypto2/Multikey.kt b/src/commonMain/kotlin/net/sergeych/crypto2/Multikey.kt
index 5e6ced5..8e55f1c 100644
--- a/src/commonMain/kotlin/net/sergeych/crypto2/Multikey.kt
+++ b/src/commonMain/kotlin/net/sergeych/crypto2/Multikey.kt
@@ -60,6 +60,12 @@ sealed class Multikey {
      */
     abstract fun check(keys: Iterable<VerifyingPublicKey>): Boolean
 
+    /**
+     * Step towards automated picking necessary keys.
+     * Return all the keys mentioned in this multikey condition.
+     */
+    abstract fun mentionedKeys(): Set<VerifyingPublicKey>
+
     /**
      * Check that [verifyingKeys] satisfy the multikey condition
      */
@@ -97,6 +103,10 @@ sealed class Multikey {
             }
             return false
         }
+
+        override fun mentionedKeys(): Set<VerifyingPublicKey> {
+            return validKeys
+        }
     }
 
     /**
@@ -119,6 +129,10 @@ sealed class Multikey {
             }
             return false
         }
+
+        override fun mentionedKeys(): Set<VerifyingPublicKey> {
+            return validKeys.flatMap { it.mentionedKeys() }.toSet()
+        }
     }
 
     /**
@@ -129,6 +143,7 @@ sealed class Multikey {
     @Serializable
     object AnyKey : Multikey() {
         override fun check(keys: Iterable<VerifyingPublicKey>): Boolean = true
+        override fun mentionedKeys(): Set<VerifyingPublicKey> = emptySet()
     }
 
 
diff --git a/src/commonMain/kotlin/net/sergeych/crypto2/Seal.kt b/src/commonMain/kotlin/net/sergeych/crypto2/Seal.kt
index ff0e3c1..aef61eb 100644
--- a/src/commonMain/kotlin/net/sergeych/crypto2/Seal.kt
+++ b/src/commonMain/kotlin/net/sergeych/crypto2/Seal.kt
@@ -10,7 +10,7 @@
 
 package net.sergeych.crypto2
 
-import kotlinx.datetime.Instant
+import kotlin.time.Instant
 import kotlinx.serialization.Serializable
 import net.sergeych.bipack.BipackEncoder
 import net.sergeych.bipack.decodeFromBipack
diff --git a/src/commonMain/kotlin/net/sergeych/crypto2/SealedBox.kt b/src/commonMain/kotlin/net/sergeych/crypto2/SealedBox.kt
index f04e95e..fbbc4ce 100644
--- a/src/commonMain/kotlin/net/sergeych/crypto2/SealedBox.kt
+++ b/src/commonMain/kotlin/net/sergeych/crypto2/SealedBox.kt
@@ -10,7 +10,7 @@
 
 package net.sergeych.crypto2
 
-import kotlinx.datetime.Instant
+import kotlin.time.Instant
 import kotlinx.serialization.Serializable
 import kotlinx.serialization.Transient
 import net.sergeych.bipack.BipackDecoder
diff --git a/src/commonMain/kotlin/net/sergeych/crypto2/SigningKey.kt b/src/commonMain/kotlin/net/sergeych/crypto2/SigningKey.kt
index 7b4e35f..8ac0880 100644
--- a/src/commonMain/kotlin/net/sergeych/crypto2/SigningKey.kt
+++ b/src/commonMain/kotlin/net/sergeych/crypto2/SigningKey.kt
@@ -10,7 +10,7 @@
 
 package net.sergeych.crypto2
 
-import kotlinx.datetime.Instant
+import kotlin.time.Instant
 
 interface SigningKey: KeyInstance {
     val verifyingKey: VerifyingPublicKey
diff --git a/src/commonMain/kotlin/net/sergeych/crypto2/SigningSecretKey.kt b/src/commonMain/kotlin/net/sergeych/crypto2/SigningSecretKey.kt
index 4f60f0c..f8966ac 100644
--- a/src/commonMain/kotlin/net/sergeych/crypto2/SigningSecretKey.kt
+++ b/src/commonMain/kotlin/net/sergeych/crypto2/SigningSecretKey.kt
@@ -11,7 +11,7 @@
 package net.sergeych.crypto2
 
 import com.ionspin.kotlin.crypto.signature.Signature
-import kotlinx.datetime.Instant
+import kotlin.time.Instant
 import kotlinx.serialization.SerialName
 import kotlinx.serialization.Serializable
 import kotlinx.serialization.Transient
diff --git a/src/commonMain/kotlin/net/sergeych/utools/time.kt b/src/commonMain/kotlin/net/sergeych/utools/time.kt
index e4c4939..6cbb74c 100644
--- a/src/commonMain/kotlin/net/sergeych/utools/time.kt
+++ b/src/commonMain/kotlin/net/sergeych/utools/time.kt
@@ -12,8 +12,8 @@
 
 package net.sergeych.utools
 
-import kotlinx.datetime.Clock
-import kotlinx.datetime.Instant
+import kotlin.time.Clock
+import kotlin.time.Instant
 
 fun now(): Instant = Clock.System.now()
 fun nowToSeconds(): Instant = Clock.System.now().truncateToSeconds()
diff --git a/src/commonTest/kotlin/HashTest.kt b/src/commonTest/kotlin/HashTest.kt
index 93eba85..2da3237 100644
--- a/src/commonTest/kotlin/HashTest.kt
+++ b/src/commonTest/kotlin/HashTest.kt
@@ -10,25 +10,17 @@
 
 import kotlinx.coroutines.flow.asFlow
 import kotlinx.coroutines.test.runTest
-import kotlinx.datetime.Clock
+import kotlin.time.Clock
 import net.sergeych.crypto2.Hash
 import net.sergeych.crypto2.initCrypto
 import kotlin.random.Random
 import kotlin.random.nextUBytes
+import kotlin.test.Ignore
 import kotlin.test.Test
 import kotlin.test.assertContentEquals
 import kotlin.test.assertEquals
 import kotlin.test.assertFalse
 
-@Suppress("UNUSED_PARAMETER", "UNUSED_VARIABLE")
-suspend fun <T> sw(label: String, f: suspend () -> T): T {
-    val t1 = Clock.System.now()
-    val result = f()
-    val t2 = Clock.System.now()
-//    println("$label: ${t2 - t1}")
-    return result
-}
-
 class HashTest {
     @Test
     fun testEqualMethods() {
@@ -77,3 +69,13 @@ class HashTest {
 
 }
 
+@Suppress("UNUSED_PARAMETER", "UNUSED_VARIABLE")
+suspend fun <T> sw(label: String, f: suspend () -> T): T {
+    val t1 = Clock.System.now()
+    val result = f()
+    val t2 = Clock.System.now()
+//    println("$label: ${t2 - t1}")
+    return result
+}
+
+
diff --git a/src/commonTest/kotlin/PackTest.kt b/src/commonTest/kotlin/PackTest.kt
index 8be7901..4e1f30b 100644
--- a/src/commonTest/kotlin/PackTest.kt
+++ b/src/commonTest/kotlin/PackTest.kt
@@ -9,7 +9,7 @@
  */
 
 import kotlinx.coroutines.test.runTest
-import kotlinx.datetime.Instant
+import kotlin.time.Instant
 import net.sergeych.crypto2.initCrypto
 import net.sergeych.utools.nowToSeconds
 import net.sergeych.utools.pack