diff --git a/src/main/kotlin/de/bixilon/pixlyzer/physics/PhysicsExtractor.kt b/src/main/kotlin/de/bixilon/pixlyzer/physics/PhysicsExtractor.kt
index 785ac23..7eb0f7e 100644
--- a/src/main/kotlin/de/bixilon/pixlyzer/physics/PhysicsExtractor.kt
+++ b/src/main/kotlin/de/bixilon/pixlyzer/physics/PhysicsExtractor.kt
@@ -70,6 +70,7 @@ object PhysicsExtractor {
         //      MixedFluidExtractor::class.java,
 
         //      DamageExtractor::class.java,
+        ChatSignatureExtractor::class.java,
         VelocityFlatteningExtractor::class.java,
         IceWalk::class.java,
         AbilitiesExtractor::class.java,
diff --git a/src/main/kotlin/de/bixilon/pixlyzer/physics/PhysicsTags.kt b/src/main/kotlin/de/bixilon/pixlyzer/physics/PhysicsTags.kt
index b5dbd76..8c962cf 100644
--- a/src/main/kotlin/de/bixilon/pixlyzer/physics/PhysicsTags.kt
+++ b/src/main/kotlin/de/bixilon/pixlyzer/physics/PhysicsTags.kt
@@ -1,7 +1,7 @@
 package de.bixilon.pixlyzer.physics
 
 import net.minecraft.block.Blocks
-import net.minecraft.tag.BlockTags
+import net.minecraft.registry.tag.BlockTags
 
 object PhysicsTags {
 
diff --git a/src/main/kotlin/de/bixilon/pixlyzer/physics/PhysicsUtil.kt b/src/main/kotlin/de/bixilon/pixlyzer/physics/PhysicsUtil.kt
index 76ab843..ec75403 100644
--- a/src/main/kotlin/de/bixilon/pixlyzer/physics/PhysicsUtil.kt
+++ b/src/main/kotlin/de/bixilon/pixlyzer/physics/PhysicsUtil.kt
@@ -27,12 +27,12 @@ import net.minecraft.client.world.ClientWorld
 import net.minecraft.entity.Entity
 import net.minecraft.network.ClientConnection
 import net.minecraft.network.NetworkSide
+import net.minecraft.registry.entry.RegistryEntry
 import net.minecraft.scoreboard.Scoreboard
 import net.minecraft.stat.StatHandler
 import net.minecraft.util.math.BlockPos
 import net.minecraft.util.math.ChunkPos
 import net.minecraft.util.profiler.DummyProfiler
-import net.minecraft.util.registry.RegistryEntry
 import net.minecraft.world.Difficulty
 import net.minecraft.world.Heightmap
 import net.minecraft.world.biome.Biome
diff --git a/src/main/kotlin/de/bixilon/pixlyzer/physics/impl/ClientWorldImpl.kt b/src/main/kotlin/de/bixilon/pixlyzer/physics/impl/ClientWorldImpl.kt
index ae242ee..4ea795d 100644
--- a/src/main/kotlin/de/bixilon/pixlyzer/physics/impl/ClientWorldImpl.kt
+++ b/src/main/kotlin/de/bixilon/pixlyzer/physics/impl/ClientWorldImpl.kt
@@ -32,7 +32,6 @@ class ClientWorldImpl private constructor() : ClientWorld(null, null, null, null
     override fun playSound(x: Double, y: Double, z: Double, event: SoundEvent?, category: SoundCategory?, volume: Float, pitch: Float, useDistance: Boolean, seed: Long) = Unit
     override fun playSoundAtBlockCenter(pos: BlockPos?, sound: SoundEvent?, category: SoundCategory?, volume: Float, pitch: Float, useDistance: Boolean) = Unit
     override fun playSoundFromEntity(except: PlayerEntity?, entity: Entity?, sound: SoundEvent?, category: SoundCategory?, volume: Float, pitch: Float) = Unit
-    override fun playSoundFromEntity(except: PlayerEntity?, entity: Entity?, sound: SoundEvent?, category: SoundCategory?, volume: Float, pitch: Float, seed: Long) = Unit
 
 
     override fun shouldUpdatePostDeath(entity: Entity?) = true
diff --git a/src/main/kotlin/de/bixilon/pixlyzer/physics/tests/BiomeNoiseExtractor.kt b/src/main/kotlin/de/bixilon/pixlyzer/physics/tests/BiomeNoiseExtractor.kt
index ea42a57..29ce9b8 100644
--- a/src/main/kotlin/de/bixilon/pixlyzer/physics/tests/BiomeNoiseExtractor.kt
+++ b/src/main/kotlin/de/bixilon/pixlyzer/physics/tests/BiomeNoiseExtractor.kt
@@ -1,7 +1,7 @@
 package de.bixilon.pixlyzer.physics.tests
 
+import net.minecraft.registry.entry.RegistryEntry
 import net.minecraft.util.math.BlockPos
-import net.minecraft.util.registry.RegistryEntry
 import net.minecraft.world.biome.Biome
 import net.minecraft.world.biome.source.BiomeAccess
 
diff --git a/src/main/kotlin/de/bixilon/pixlyzer/physics/tests/ChatSignatureExtractor.kt b/src/main/kotlin/de/bixilon/pixlyzer/physics/tests/ChatSignatureExtractor.kt
new file mode 100644
index 0000000..b149fe1
--- /dev/null
+++ b/src/main/kotlin/de/bixilon/pixlyzer/physics/tests/ChatSignatureExtractor.kt
@@ -0,0 +1,99 @@
+package de.bixilon.pixlyzer.physics.tests
+
+import de.bixilon.kutil.base64.Base64Util.fromBase64
+import de.bixilon.kutil.base64.Base64Util.toBase64
+import de.bixilon.kutil.uuid.UUIDUtil.toUUID
+import net.minecraft.network.encryption.Signer
+import net.minecraft.network.message.LastSeenMessageList
+import net.minecraft.network.message.MessageBody
+import net.minecraft.network.message.MessageChain
+import net.minecraft.network.message.MessageSignatureData
+import java.security.KeyFactory
+import java.security.spec.PKCS8EncodedKeySpec
+import java.time.Instant
+import java.util.*
+
+class ChatSignatureExtractor : AbstractExtractor() {
+    val stringKey = System.getenv("PRIVATE_KEY")
+    private val key = KeyFactory.getInstance("RSA").generatePrivate(PKCS8EncodedKeySpec(stringKey.replace("\n", "").replace("\\n", "").removePrefix("-----BEGIN RSA PRIVATE KEY-----").removeSuffix("-----END RSA PRIVATE KEY-----").fromBase64()))
+    private val uuid = "9e6ce7c5-40d3-483e-8e5a-b6350987d65f".toUUID()
+
+
+    @ExtractorMethod
+    fun singing1() {
+        val message = "bixilon began the development during lockdown"
+        val time = Instant.ofEpochMilli(1673102470_1234)
+        val sessionId = "a26b7114-36c4-4eea-acac-108f516ef72d".toUUID()
+
+        val packer = MessageChain(uuid, sessionId).getPacker(Signer.create(this.key, "SHA256withRSA"))
+        val signature = packer.pack(MessageBody(message, time, -4886770986649219020L, LastSeenMessageList.EMPTY))!!
+        result["signature"] = signature.data.toBase64()
+    }
+
+    @ExtractorMethod
+    fun singing2() {
+        val message = "reversing signature code is pita"
+        val time = Instant.ofEpochMilli(1673103191_5678)
+        val sessionId = "79f3da83-a6a1-4d55-9aca-39d5faf4ad8b".toUUID()
+
+
+        val packer = MessageChain(uuid, sessionId).getPacker(Signer.create(this.key, "SHA256withRSA"))
+        val signature = packer.pack(MessageBody(message, time, 1856442944183750824L, LastSeenMessageList.EMPTY))!!
+        result["signature"] = signature.data.toBase64()
+    }
+
+    @ExtractorMethod
+    fun singing3() {
+        val message = "now even with last seen messages. I don't know their purpose."
+        val time = Instant.ofEpochMilli(1673103854_8402)
+        val sessionId = "5c31705b-963c-4832-b8a5-1ee617a4b362".toUUID()
+
+        val lastSeen = LastSeenMessageList(mutableListOf(MessageSignatureData("/OmblHW9CwdAawdE7WtVurRs7umsa/my8EeTT/NY36lqg3HmtAsqyRQ4fXHelw6pOA4o8UroAlmx+inwiEFHXkDICEIVM69vHKapQvoAaeEVrQ4pn9vURTY3GcUVOgr12V3d00odEpwviXaF6kchG1b/pZsLsfpacMiiVHkxZoqolvUNifHQKXVS48Gu1AKkwRw6bkcOKYZpcZgffe6U273rEQQefwzIdT/8F1P04WhiH7SREexVOolkuoKo6gYxXELf5M0BUf0ssG3SS1k8Wr3ys9nzB6hSoEd/ftKqGVxoqeq7pd1GgKfaRWpka8ZNyDpdm8JqvrmlN/phpS5X4Q==".fromBase64()))) // uuid does not matter, bytes are random
+
+
+        val packer = MessageChain(uuid, sessionId).getPacker(Signer.create(this.key, "SHA256withRSA"))
+        val signature = packer.pack(MessageBody(message, time, 6392082609L, lastSeen))!!
+        result["signature"] = signature.data.toBase64()
+    }
+
+    @ExtractorMethod
+    fun singing4() {
+        val message = "ʞ⍧\uDB16\uDFB1іⴎO\uD85E\uDF9A!㛽J˻5&뻝\uD8B9\uDE8F\uDA0C\uDC41\uDB9B\uDD0Fi읣މ猣랒糓\uD8EF\uDFCFk\uDA1D\uDCA4썿ߛ믣Ȣ\uDA51\uDF5B4" // random utf8 chars
+        val time = Instant.ofEpochMilli(1739579479_6302)
+        val sessionId = "232170f7-ef39-4959-bf4a-354145b9483a".toUUID()
+
+
+        val packer = MessageChain(uuid, sessionId).getPacker(Signer.create(this.key, "SHA256withRSA"))
+        val signature = packer.pack(MessageBody(message, time, 6392082609L, LastSeenMessageList.EMPTY))!!
+        result["signature"] = signature.data.toBase64()
+    }
+
+    @ExtractorMethod
+    fun singing5() {
+        val messages = listOf(
+            Pair(
+                "this is the first message :)",
+                Instant.ofEpochMilli(1673104584_7491),
+            ),
+            Pair(
+                "this is the second message :)",
+                Instant.ofEpochMilli(1673104585_7492),
+            ),
+            Pair(
+                "this is the third and last message :)",
+                Instant.ofEpochMilli(1673104586_7493),
+            )
+        )
+
+        val sessionId = "de2f95c2-8730-47ba-a5aa-8db09fcec48e".toUUID()
+
+
+        val packer = MessageChain(uuid, sessionId).getPacker(Signer.create(this.key, "SHA256withRSA"))
+
+        val signatures: MutableList<String> = mutableListOf()
+        for ((message, time) in messages) {
+            signatures += packer.pack(MessageBody(message, time, 6392082609L, LastSeenMessageList.EMPTY))!!.data.toBase64()
+        }
+        result["signature"] = signatures
+    }
+}
diff --git a/src/main/kotlin/de/bixilon/pixlyzer/physics/tests/blocks/climbing/ClimbingExtractor.kt b/src/main/kotlin/de/bixilon/pixlyzer/physics/tests/blocks/climbing/ClimbingExtractor.kt
index 1eaa5a1..8d0e0bc 100644
--- a/src/main/kotlin/de/bixilon/pixlyzer/physics/tests/blocks/climbing/ClimbingExtractor.kt
+++ b/src/main/kotlin/de/bixilon/pixlyzer/physics/tests/blocks/climbing/ClimbingExtractor.kt
@@ -4,7 +4,7 @@ import de.bixilon.pixlyzer.physics.tests.AbstractExtractor
 import net.minecraft.block.BlockState
 import net.minecraft.block.Blocks
 import net.minecraft.block.TrapdoorBlock
-import net.minecraft.tag.BlockTags
+import net.minecraft.registry.tag.BlockTags
 
 abstract class ClimbingExtractor(protected val block: BlockState) : AbstractExtractor() {
 
diff --git a/src/main/kotlin/de/bixilon/pixlyzer/physics/tests/fluid/FluidUtil.kt b/src/main/kotlin/de/bixilon/pixlyzer/physics/tests/fluid/FluidUtil.kt
index 7b80361..c6499e0 100644
--- a/src/main/kotlin/de/bixilon/pixlyzer/physics/tests/fluid/FluidUtil.kt
+++ b/src/main/kotlin/de/bixilon/pixlyzer/physics/tests/fluid/FluidUtil.kt
@@ -3,7 +3,7 @@ package de.bixilon.pixlyzer.physics.tests.fluid
 import net.minecraft.block.BlockState
 import net.minecraft.block.FluidBlock
 import net.minecraft.fluid.Fluid
-import net.minecraft.tag.TagKey
+import net.minecraft.registry.tag.TagKey
 
 object FluidUtil {
 
diff --git a/src/main/kotlin/de/bixilon/pixlyzer/physics/tests/fluid/still/LavaStillExtractor.kt b/src/main/kotlin/de/bixilon/pixlyzer/physics/tests/fluid/still/LavaStillExtractor.kt
index a92e2c2..435da5c 100644
--- a/src/main/kotlin/de/bixilon/pixlyzer/physics/tests/fluid/still/LavaStillExtractor.kt
+++ b/src/main/kotlin/de/bixilon/pixlyzer/physics/tests/fluid/still/LavaStillExtractor.kt
@@ -3,7 +3,7 @@ package de.bixilon.pixlyzer.physics.tests.fluid.still
 import de.bixilon.kutil.cast.CastUtil.unsafeCast
 import de.bixilon.pixlyzer.physics.tests.ExtractorMethod
 import net.minecraft.block.Blocks
-import net.minecraft.tag.FluidTags
+import net.minecraft.registry.tag.FluidTags
 
 class LavaStillExtractor : StillFluidExtractor(Blocks.LAVA.unsafeCast(), FluidTags.LAVA) {
 
diff --git a/src/main/kotlin/de/bixilon/pixlyzer/physics/tests/fluid/still/MixedFluidExtractor.kt b/src/main/kotlin/de/bixilon/pixlyzer/physics/tests/fluid/still/MixedFluidExtractor.kt
index f560296..67fee39 100644
--- a/src/main/kotlin/de/bixilon/pixlyzer/physics/tests/fluid/still/MixedFluidExtractor.kt
+++ b/src/main/kotlin/de/bixilon/pixlyzer/physics/tests/fluid/still/MixedFluidExtractor.kt
@@ -7,7 +7,7 @@ import de.bixilon.pixlyzer.physics.tests.fluid.FluidUtil.addTags
 import de.bixilon.pixlyzer.physics.tests.fluid.FluidUtil.withLevel
 import net.minecraft.block.Blocks
 import net.minecraft.block.FluidBlock
-import net.minecraft.tag.FluidTags
+import net.minecraft.registry.tag.FluidTags
 
 class MixedFluidExtractor : AbstractExtractor() {
     private val lava = Blocks.LAVA.unsafeCast<FluidBlock>()
diff --git a/src/main/kotlin/de/bixilon/pixlyzer/physics/tests/fluid/still/StillFluidExtractor.kt b/src/main/kotlin/de/bixilon/pixlyzer/physics/tests/fluid/still/StillFluidExtractor.kt
index d63137e..394bade 100644
--- a/src/main/kotlin/de/bixilon/pixlyzer/physics/tests/fluid/still/StillFluidExtractor.kt
+++ b/src/main/kotlin/de/bixilon/pixlyzer/physics/tests/fluid/still/StillFluidExtractor.kt
@@ -6,7 +6,7 @@ import de.bixilon.pixlyzer.physics.tests.fluid.FluidUtil.withLevel
 import net.minecraft.block.Blocks
 import net.minecraft.block.FluidBlock
 import net.minecraft.fluid.Fluid
-import net.minecraft.tag.TagKey
+import net.minecraft.registry.tag.TagKey
 
 abstract class StillFluidExtractor(
     protected val fluid: FluidBlock,
diff --git a/src/main/kotlin/de/bixilon/pixlyzer/physics/tests/fluid/still/WaterStillExtractor.kt b/src/main/kotlin/de/bixilon/pixlyzer/physics/tests/fluid/still/WaterStillExtractor.kt
index 9e6ca30..8398ca4 100644
--- a/src/main/kotlin/de/bixilon/pixlyzer/physics/tests/fluid/still/WaterStillExtractor.kt
+++ b/src/main/kotlin/de/bixilon/pixlyzer/physics/tests/fluid/still/WaterStillExtractor.kt
@@ -3,7 +3,7 @@ package de.bixilon.pixlyzer.physics.tests.fluid.still
 import de.bixilon.kutil.cast.CastUtil.unsafeCast
 import de.bixilon.pixlyzer.physics.tests.ExtractorMethod
 import net.minecraft.block.Blocks
-import net.minecraft.tag.FluidTags
+import net.minecraft.registry.tag.FluidTags
 
 class WaterStillExtractor : StillFluidExtractor(Blocks.WATER.unsafeCast(), FluidTags.WATER) {