diff --git a/hwe/ts/util/LiteHashDRBG.ts b/hwe/ts/util/LiteHashDRBG.ts
index 13df8e6a..251f66e2 100644
--- a/hwe/ts/util/LiteHashDRBG.ts
+++ b/hwe/ts/util/LiteHashDRBG.ts
@@ -85,7 +85,17 @@ export class LiteHashDRBG implements RNG {
     protected hq: DataView;
     protected hqIdxPos: number;
 
-    public constructor(protected seed: MaybeBytes, protected stateIdx = 0) {
+    public constructor(protected seed: MaybeBytes, protected stateIdx = 0, bufferIdx = 0) {
+        if(bufferIdx < 0){
+            throw new Error(`bufferIdx ${bufferIdx} < 0`);
+        }
+        if(bufferIdx >= bufferByteSize){
+            throw new Error(`bufferidx ${bufferIdx} >= ${bufferByteSize}`);
+        }
+        if(stateIdx < 0){
+            throw new Error(`stateIdx ${stateIdx} < 0`);
+        }
+
         const seedU8 = (() => {
             if (seed instanceof Uint8Array) {
                 return seed;
@@ -106,6 +116,7 @@ export class LiteHashDRBG implements RNG {
         this.hqIdxPos = seedU8.byteLength;
 
         this.genNextBlock();
+        this.bufferIdx = bufferIdx;
     }
 
     protected genNextBlock(): void {
diff --git a/src/sammo/LiteHashDRBG.php b/src/sammo/LiteHashDRBG.php
index c46b8f87..35aaa3f5 100644
--- a/src/sammo/LiteHashDRBG.php
+++ b/src/sammo/LiteHashDRBG.php
@@ -21,9 +21,19 @@ class LiteHashDRBG implements RNG
 
     protected string $buffer;
     protected int $bufferIdx;
-    public function __construct(protected string $seed, protected int $stateIdx = 0)
+    public function __construct(protected string $seed, protected int $stateIdx = 0, int $bufferIdx = 0)
     {
+        if($bufferIdx < 0){
+            throw new \InvalidArgumentException("bufferIdx {$bufferIdx} < 0");
+        }
+        if($bufferIdx >= self::BUFFER_BYTE_SIZE){
+            throw new \InvalidArgumentException("bufferIdx {$bufferIdx} >= ".self::BUFFER_BYTE_SIZE);
+        }
+        if($stateIdx < 0){
+            throw new \InvalidArgumentException("stateIdx {$stateIdx} < 0");
+        }
         $this->genNextBlock();
+        $this->bufferIdx = $bufferIdx;
     }
 
     protected function genNextBlock(): void