diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 7533de2..6fb017d 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -21,7 +21,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest]
-        scala: [3.3.1, 2.13.12, 2.12.18, 2.11.12]
+        scala: [3.3.5, 2.13.16, 2.12.20, 2.11.12]
         java: [adopt@1.8]
     runs-on: ${{ matrix.os }}
     steps:
@@ -64,7 +64,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest]
-        scala: [3.3.1, 2.13.12]
+        scala: [3.3.5, 2.13.16]
         java: [adopt@1.8]
     runs-on: ${{ matrix.os }}
     steps:
diff --git a/build.sbt b/build.sbt
index c1576ab..ac5c7e1 100644
--- a/build.sbt
+++ b/build.sbt
@@ -103,10 +103,11 @@ lazy val scalac3: Seq[String] = Seq(
   "-source:3.0-migration" // makes the compiler forgiving on most of the dropped features, printing warnings in place of errors
 )
 
-lazy val scala213 = "2.13.12"
-lazy val scala212 = "2.12.18"
+lazy val scala213 = "2.13.16"
+lazy val scala212 = "2.12.20"
 lazy val scala211 = "2.11.12"
-lazy val scala3   = "3.3.1"
+lazy val scala3   = "3.3.5"
+lazy val scalatestVersion = "3.2.19"
 
 crossScalaVersions := Seq(scala211, scala212, scala213, scala3)
 scalaVersion := scala213
@@ -125,30 +126,27 @@ lazy val utilSettings = Seq(
 
   resolvers ++= Resolver.sonatypeOssRepos("snapshots"),
   libraryDependencies ++= Seq(
-    ("org.rudogma" %%% "supertagged" % "2.0-RC2").cross(CrossVersion.for3Use2_13),
+    "org.scalatest" %%% "scalatest" % scalatestVersion % Test,
+    "org.scalatest" %%% "scalatest-propspec" % scalatestVersion % Test,
+    "org.scalatest" %%% "scalatest-shouldmatchers" % scalatestVersion % Test
   ) ++ {
     if (scalaVersion.value == scala3)
       Seq(
-        "org.scalatest" %%% "scalatest" % "3.3.0-alpha.1" % Test,
-        "org.scalatest" %%% "scalatest-propspec" % "3.3.0-alpha.1" % Test,
-        "org.scalatest" %%% "scalatest-shouldmatchers" % "3.3.0-alpha.1" % Test,
-        "org.scalacheck" %%% "scalacheck" % "1.15.3" % Test,
-        "org.scalatestplus" %%% "scalacheck-1-17" % "3.3.0.0-alpha.1" % Test
+        "org.scalacheck" %%% "scalacheck" % "1.18.1" % Test,
+        "org.scalatestplus" %%% "scalacheck-1-18" % "3.2.19.0" % Test
       )
     else // use last versions with Scala 2.11 support
       Seq(
-        "org.scalatest" %%% "scalatest" % "3.3.0-SNAP3" % Test,
-        "org.scalatest" %%% "scalatest-propspec" % "3.3.0-SNAP3" % Test,
-        "org.scalatest" %%% "scalatest-shouldmatchers" % "3.3.0-SNAP3" % Test,
+        "org.rudogma" %%% "supertagged" % "2.0-RC2",
         "org.scalacheck" %%% "scalacheck" % "1.15.2" % Test,
         "org.scalatestplus" %%% "scalacheck-1-15" % "3.3.0.0-SNAP3" % Test
       )
   },
   scalacOptions ++= {
     CrossVersion.partialVersion(scalaVersion.value) match {
-      case Some((2, n)) if n == 13 =>
+      case Some((2, 13)) =>
         scalac ++ scalac213
-      case Some((2, n)) if n == 12 =>
+      case Some((2, 12)) =>
         scalac ++ scalac212
       case Some((2, 11)) =>
         scalac ++ scalac211
diff --git a/project/build.properties b/project/build.properties
index 3c0b78a..73df629 100644
--- a/project/build.properties
+++ b/project/build.properties
@@ -1 +1 @@
-sbt.version=1.9.1
+sbt.version=1.10.7
diff --git a/project/plugins.sbt b/project/plugins.sbt
index 8b1c598..b4912c1 100644
--- a/project/plugins.sbt
+++ b/project/plugins.sbt
@@ -1,8 +1,8 @@
-addSbtPlugin("org.scoverage" % "sbt-scoverage" % "1.6.1")
-addSbtPlugin("org.scoverage" % "sbt-coveralls" % "1.2.7")
-addSbtPlugin("net.virtual-void" % "sbt-dependency-graph" % "0.9.2")
-addSbtPlugin("org.xerial.sbt" % "sbt-sonatype" % "3.8")
-addSbtPlugin("com.jsuereth" % "sbt-pgp" % "2.0.0")
-addSbtPlugin("com.dwijnand" % "sbt-dynver" % "4.1.1")
-addSbtPlugin("org.portable-scala" % "sbt-scalajs-crossproject" % "1.3.1")
-addSbtPlugin("org.scala-js"       % "sbt-scalajs"              % "1.13.2")
+addDependencyTreePlugin
+addSbtPlugin("org.scoverage" % "sbt-scoverage" % "2.3.0")
+addSbtPlugin("org.scoverage" % "sbt-coveralls" % "1.3.15")
+addSbtPlugin("org.xerial.sbt" % "sbt-sonatype" % "3.12.2")
+addSbtPlugin("com.github.sbt" % "sbt-pgp" % "2.3.1")
+addSbtPlugin("com.github.sbt" % "sbt-dynver" % "5.1.0")
+addSbtPlugin("org.portable-scala" % "sbt-scalajs-crossproject" % "1.3.2")
+addSbtPlugin("org.scala-js"       % "sbt-scalajs"              % "1.18.2")
diff --git a/shared/src/main/scala/scorex/util/package.scala b/shared/src/main/scala-2/scorex/util/package.scala
similarity index 100%
rename from shared/src/main/scala/scorex/util/package.scala
rename to shared/src/main/scala-2/scorex/util/package.scala
diff --git a/shared/src/main/scala-3/scorex/util/package.scala b/shared/src/main/scala-3/scorex/util/package.scala
new file mode 100644
index 0000000..9f291a5
--- /dev/null
+++ b/shared/src/main/scala-3/scorex/util/package.scala
@@ -0,0 +1,20 @@
+package scorex
+
+import scorex.util.encode.Base16
+
+opaque type ModifierId <: String = String
+object ModifierId {
+  def apply(s: String): ModifierId = s
+}
+
+def bytesToId(bytes: Array[Byte]): ModifierId = ModifierId(Base16.encode(bytes))
+
+def idToBytes(id: ModifierId): Array[Byte] = Base16.decode(id).get
+
+extension (m: ModifierId) {
+  @inline def toBytes: Array[Byte] = idToBytes(m)
+}
+
+extension (bytes: Array[Byte]) {
+  @inline def toModifierId: ModifierId = bytesToId(bytes)
+}
\ No newline at end of file
diff --git a/shared/src/main/scala/scorex/util/Extensions.scala b/shared/src/main/scala/scorex/util/Extensions.scala
index 050faf6..d746028 100644
--- a/shared/src/main/scala/scorex/util/Extensions.scala
+++ b/shared/src/main/scala/scorex/util/Extensions.scala
@@ -74,6 +74,7 @@ object Extensions {
       * If `Long` value is out of the possible range for a [[scala.Int]] result,
       * then a `java.lang.ArithmeticException` is thrown.
       */
+    @deprecated("Use Reader#getUIntExact() instead")
     def toIntExact: Int = {
       if (x < Int.MinValue || x > Int.MaxValue)
         throw new ArithmeticException("Int overflow")
@@ -86,7 +87,7 @@ object Extensions {
 
     /**
       * Safely casting each element of collection to be type of `B`.
-      * If element can not to be cast to `B` then `AssertionError` is thrown
+      * If element can not to be cast to `B` then `IllegalArgumentException` is thrown
       */
     def cast[B:ClassTag]: Source[B] = {
 
diff --git a/shared/src/main/scala/scorex/util/serialization/Reader.scala b/shared/src/main/scala/scorex/util/serialization/Reader.scala
index c44dd2a..410d365 100644
--- a/shared/src/main/scala/scorex/util/serialization/Reader.scala
+++ b/shared/src/main/scala/scorex/util/serialization/Reader.scala
@@ -68,8 +68,15 @@ abstract class Reader {
     * Decode positive Int.
     * @return signed Long
     */
+  @deprecated("Use getUIntExact() instead")
   def getUInt(): Long
 
+  /**
+    * Decode positive Int.
+    * @return unsigned 31-bit Int
+    */
+  def getUIntExact(): Int
+
   /**
     * Decode signed Long.
     * @return signed Long
diff --git a/shared/src/main/scala/scorex/util/serialization/VLQReader.scala b/shared/src/main/scala/scorex/util/serialization/VLQReader.scala
index 84bd942..becbf1d 100644
--- a/shared/src/main/scala/scorex/util/serialization/VLQReader.scala
+++ b/shared/src/main/scala/scorex/util/serialization/VLQReader.scala
@@ -25,7 +25,7 @@ trait VLQReader extends Reader {
     * Decode Short previously encoded with [[VLQWriter.putUShort]] using VLQ.
     * @see [[https://en.wikipedia.org/wiki/Variable-length_quantity]]
     * @return Int
-    * @throws AssertionError for deserialized values not in unsigned Short range
+    * @throws IllegalArgumentException for deserialized values not in unsigned Short range
     */
   @inline override def getUShort(): Int = {
     val x = getULong().toInt
@@ -50,6 +50,7 @@ trait VLQReader extends Reader {
     * Decode Int previously encoded with [[VLQWriter.putUInt]] using VLQ.
     * @see [[https://en.wikipedia.org/wiki/Variable-length_quantity]]
     * @return Long
+    * @throws IllegalArgumentException for deserialized values not in unsigned Int range
     */
   @inline override def getUInt(): Long = {
     val x = getULong()
@@ -57,6 +58,18 @@ trait VLQReader extends Reader {
     x
   }
 
+  /**
+    * Decode Int previously encoded with [[VLQWriter.putUInt]] using VLQ.
+    * @see [[https://en.wikipedia.org/wiki/Variable-length_quantity]]
+    * @return Int
+    * @throws IllegalArgumentException for deserialized values not in unsigned 31-bit Int range
+    */
+  @inline override def getUIntExact(): Int = {
+    val x = getULong()
+    require(x >= 0L && x <= Int.MaxValue.toLong, s"$x is out of unsigned 31-bit int range")
+    x.toInt
+  }
+
   /**
     * Decode signed Long previously encoded with [[VLQWriter.putLong]] using VLQ with ZigZag.
     *
diff --git a/shared/src/main/scala/scorex/util/serialization/VLQWriter.scala b/shared/src/main/scala/scorex/util/serialization/VLQWriter.scala
index 82f26e7..666ac7a 100644
--- a/shared/src/main/scala/scorex/util/serialization/VLQWriter.scala
+++ b/shared/src/main/scala/scorex/util/serialization/VLQWriter.scala
@@ -31,7 +31,7 @@ trait VLQWriter extends Writer {
     *
     * @see [[https://en.wikipedia.org/wiki/Variable-length_quantity]]
     * @param x unsigned Short in a range 0 <= x <= 0xFFFF represented as Int
-    * @throws AssertionError for values not in unsigned Short range
+    * @throws IllegalArgumentException for values not in unsigned Short range
     */
   @inline override def putUShort(x: Int): this.type = {
     require(x >= 0 && x <= 0xFFFF, s"Value $x is out of unsigned short range")
@@ -59,7 +59,7 @@ trait VLQWriter extends Writer {
     *
     * @see [[https://en.wikipedia.org/wiki/Variable-length_quantity]]
     * @param x unsigned Int
-    * @throws AssertionError for values not in unsigned Int range
+    * @throws IllegalArgumentException for values not in unsigned Int range
     */
   @inline override def putUInt(x: Long): this.type = {
     require(x >= 0 && x <= 0xFFFFFFFFL, s"$x is out of unsigned int range")
@@ -151,7 +151,7 @@ trait VLQWriter extends Writer {
     * Encode String is shorter than 256 bytes
     *
     * @param s String
-    * @return
+    * @throws IllegalArgumentException for strings longer than 255 bytes
     */
   override def putShortString(s: String): this.type = {
     val bytes = s.getBytes
diff --git a/shared/src/main/scala/scorex/util/serialization/Writer.scala b/shared/src/main/scala/scorex/util/serialization/Writer.scala
index 8dc9fa3..b2b6fb2 100644
--- a/shared/src/main/scala/scorex/util/serialization/Writer.scala
+++ b/shared/src/main/scala/scorex/util/serialization/Writer.scala
@@ -46,7 +46,7 @@ abstract class Writer {
     * Encode integer as an unsigned byte asserting the range check
     * @param x integer value to encode
     * @return
-    * @throws AssertionError if x is outside of the unsigned byte range
+    * @throws IllegalArgumentException if x is outside of the unsigned byte range
     */
   def putUByte(x: Int): this.type = {
     require(x >= 0 && x <= 0xFF, s"$x is out of unsigned byte range")
diff --git a/shared/src/test/scala/scorex/util/serialization/VLQReaderWriterSpecification.scala b/shared/src/test/scala/scorex/util/serialization/VLQReaderWriterSpecification.scala
index 01ff74a..1a39a08 100644
--- a/shared/src/test/scala/scorex/util/serialization/VLQReaderWriterSpecification.scala
+++ b/shared/src/test/scala/scorex/util/serialization/VLQReaderWriterSpecification.scala
@@ -338,6 +338,18 @@ trait VLQReaderWriterSpecification extends AnyPropSpec
     }
   }
 
+  property("unsigned Int roundtrip exact"){
+    forAll(Gen.chooseNum(0, Int.MaxValue)) { x: Int =>
+      byteBufReader(byteArrayWriter().putUInt(x.toLong).toBytes).getUIntExact() shouldBe x
+    }
+    forAll(Gen.chooseNum(Long.MinValue, -1L)) { x: Long =>
+      an[IllegalArgumentException] should be thrownBy byteBufReader(byteArrayWriter().putULong(x).toBytes).getUIntExact()
+    }
+    forAll(Gen.chooseNum(Int.MaxValue.toLong + 1L, Long.MaxValue)) { x: Long =>
+      an[IllegalArgumentException] should be thrownBy byteBufReader(byteArrayWriter().putULong(x).toBytes).getUIntExact()
+    }
+  }
+
   property("Long roundtrip") {
     forAll { (v: Long) => byteBufReader(byteArrayWriter().putLong(v).toBytes).getLong() shouldBe v }
   }