diff --git a/generate-proof.sh b/generate-proof.sh
index e1ae44f..e97cfbb 100755
--- a/generate-proof.sh
+++ b/generate-proof.sh
@@ -21,9 +21,11 @@ generate_with_ots_cli() {
     local hash="$1"
     local output="$2"
     
-    # Create a temporary file with the hash
+    # Create a temporary file with the hash (convert hex to binary)
     local temp_file=$(mktemp)
-    echo -n "$hash" | xxd -r -p > "$temp_file"
+    
+    # Use python3 for hex to binary conversion (more portable than xxd)
+    python3 -c "import sys; sys.stdout.buffer.write(bytes.fromhex('$hash'))" > "$temp_file"
     
     # Generate timestamp
     ots stamp "$temp_file" -o "$output"
diff --git a/test.txt b/test.txt
new file mode 100644
index 0000000..ed1eb04
--- /dev/null
+++ b/test.txt
@@ -0,0 +1 @@
+# Test file