diff --git a/integration_tests/helpers/baseNodeProcess.js b/integration_tests/helpers/baseNodeProcess.js
index f10b2f5cd3..059dd81b14 100644
--- a/integration_tests/helpers/baseNodeProcess.js
+++ b/integration_tests/helpers/baseNodeProcess.js
@@ -144,7 +144,6 @@ class BaseNodeProcess {
       }
 
       let overrides = this.excludeTestEnvars ? {} : this.getOverrides();
-      console.error(overrides);
 
       // clear the .env file
       fs.writeFileSync(`${this.baseDir}/.overrides`, "");
diff --git a/integration_tests/helpers/domainHasher.js b/integration_tests/helpers/domainHasher.js
new file mode 100644
index 0000000000..cb2d40ddb9
--- /dev/null
+++ b/integration_tests/helpers/domainHasher.js
@@ -0,0 +1,46 @@
+/*
+ * // Copyright 2022. The Tari Project
+ * //
+ * // Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
+ * // following conditions are met:
+ * //
+ * // 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following
+ * // disclaimer.
+ * //
+ * // 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the
+ * // following disclaimer in the documentation and/or other materials provided with the distribution.
+ * //
+ * // 3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote
+ * // products derived from this software without specific prior written permission.
+ * //
+ * // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * // INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * // DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * // SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * // WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
+ * // USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+const { blake2bInit, blake2bUpdate, blake2bFinal } = require("blakejs");
+const { toLittleEndian } = require("./util");
+class DomainHasher {
+  constructor(label, output_len = 32, key = null) {
+    this.hasher = blake2bInit(output_len, key);
+    this.chain(Buffer.from(label, "utf-8"));
+  }
+
+  chain(value) {
+    let buf = Buffer.from(value);
+    let le = toLittleEndian(buf.length, 64);
+    blake2bUpdate(this.hasher, le);
+    blake2bUpdate(this.hasher, buf);
+    return this;
+  }
+
+  finalize() {
+    return blake2bFinal(this.hasher);
+  }
+}
+
+module.exports = DomainHasher;
diff --git a/integration_tests/helpers/transactionBuilder.js b/integration_tests/helpers/transactionBuilder.js
index 431afda319..7fb1f8f865 100644
--- a/integration_tests/helpers/transactionBuilder.js
+++ b/integration_tests/helpers/transactionBuilder.js
@@ -1,13 +1,14 @@
 // Copyright 2022 The Tari Project
 // SPDX-License-Identifier: BSD-3-Clause
 
-var tari_crypto = require("tari_crypto");
-var { blake2bInit, blake2bUpdate, blake2bFinal } = require("blakejs");
+const tari_crypto = require("tari_crypto");
+const { blake2bInit, blake2bUpdate, blake2bFinal } = require("blakejs");
 const {
   toLittleEndian,
   littleEndianHexStringToBigEndianHexString,
   combineTwoTariKeys,
 } = require("../helpers/util");
+const DomainHasher = require("../helpers/domainHasher");
 const { OutputType } = require("./types");
 
 class TransactionBuilder {
@@ -78,6 +79,9 @@ class TransactionBuilder {
   }
 
   toLengthEncoded(buf) {
+    if (buf.length > 127) {
+      throw new Error("toLengthEncoded: Buffer too long");
+    }
     // TODO: varint encoding, this is only valid up to len=127
     return Buffer.concat([Buffer.from([buf.length]), buf]);
   }
@@ -91,23 +95,24 @@ class TransactionBuilder {
     covenant,
     encryptedValue
   ) {
-    const KEY = null; // optional key
-    const OUTPUT_LENGTH = 32; // bytes
-    const context = blake2bInit(OUTPUT_LENGTH, KEY);
     const buf_nonce = Buffer.from(publicNonce, "hex");
     const script_offset_public_key = Buffer.from(scriptOffsetPublicKey, "hex");
     const features_buffer = this.featuresToConsensusBytes(features);
 
     // base_layer/core/src/transactions/transaction/transaction_output.rs
-    blake2bUpdate(context, buf_nonce);
-    blake2bUpdate(context, this.toLengthEncoded(script));
-    blake2bUpdate(context, features_buffer);
-    blake2bUpdate(context, script_offset_public_key);
-    blake2bUpdate(context, commitment);
-    blake2bUpdate(context, this.toLengthEncoded(covenant));
-    blake2bUpdate(context, encryptedValue);
-    const final = blake2bFinal(context);
-    return Buffer.from(final).toString("hex");
+    let hash = new DomainHasher(
+      "com.tari.base_layer.core.transactions.v0.metadata_signature"
+    )
+      .chain(buf_nonce)
+      .chain(this.toLengthEncoded(script))
+      .chain(features_buffer)
+      .chain(script_offset_public_key)
+      .chain(commitment)
+      .chain(this.toLengthEncoded(covenant))
+      .chain(encryptedValue)
+      .finalize();
+
+    return Buffer.from(hash).toString("hex");
   }
 
   buildScriptChallenge(
@@ -117,18 +122,19 @@ class TransactionBuilder {
     public_key,
     commitment
   ) {
-    let KEY = null; // optional key
-    let OUTPUT_LENGTH = 32; // bytes
-    let context = blake2bInit(OUTPUT_LENGTH, KEY);
     let buff_publicNonce = Buffer.from(publicNonce, "hex");
     let buff_public_key = Buffer.from(public_key, "hex");
-    blake2bUpdate(context, buff_publicNonce);
-    blake2bUpdate(context, this.toLengthEncoded(script));
-    blake2bUpdate(context, this.toLengthEncoded(input_data));
-    blake2bUpdate(context, buff_public_key);
-    blake2bUpdate(context, commitment);
-    let final = blake2bFinal(context);
-    return Buffer.from(final).toString("hex");
+    let hash = new DomainHasher(
+      "com.tari.base_layer.core.transactions.v0.script_challenge"
+    )
+      .chain(buff_publicNonce)
+      .chain(this.toLengthEncoded(script))
+      .chain(this.toLengthEncoded(input_data))
+      .chain(buff_public_key)
+      .chain(commitment)
+      .finalize();
+
+    return Buffer.from(hash).toString("hex");
   }
 
   hashOutput(features, commitment, script, sender_offset_public_key) {
diff --git a/integration_tests/helpers/util.js b/integration_tests/helpers/util.js
index 46605eed6b..17a58dfada 100644
--- a/integration_tests/helpers/util.js
+++ b/integration_tests/helpers/util.js
@@ -176,6 +176,11 @@ function toLittleEndian(n, numBits) {
       buf.writeUInt32LE(n);
       return buf;
     }
+    case 64: {
+      let buf = Buffer.alloc(numBits / 8);
+      buf.writeUInt64LE(n);
+      return buf;
+    }
     default: {
       const s = toLittleEndianInner(n);