diff --git a/src/Transaction.php b/src/Transaction.php
index a15a923..a3832b9 100644
--- a/src/Transaction.php
+++ b/src/Transaction.php
@@ -16,6 +16,7 @@
 use kornrunner\Keccak;
 use Web3p\RLP\RLP;
 use Elliptic\EC;
+use Elliptic\EC\KeyPair;
 use ArrayAccess;
 
 class Transaction implements ArrayAccess
@@ -68,6 +69,13 @@ class Transaction implements ArrayAccess
      */
     protected $secp256k1;
 
+    /**
+     * privateKey
+     * 
+     * @var \Elliptic\EC\KeyPair
+     */
+    protected $privateKey;
+
     /**
      * construct
      * 
@@ -253,8 +261,8 @@ public function serialize()
     public function sign(string $privateKey)
     {
         $txHash = $this->hash(false);
-        $key = $this->secp256k1->keyFromPrivate($privateKey, 'hex');
-        $signature = $key->sign($txHash);
+        $privateKey = $this->secp256k1->keyFromPrivate($privateKey, 'hex');
+        $signature = $privateKey->sign($txHash);
         $r = $signature->r;
         $s = $signature->s;
         $v = $signature->recoveryParam + 35;
@@ -268,6 +276,7 @@ public function sign(string $privateKey)
         $this->offsetSet('r', '0x' . $r->toString(16));
         $this->offsetSet('s', '0x' . $s->toString(16));
         $this->offsetSet('v', $v);
+        $this->privateKey = $privateKey;
 
         return $this->serialize()->toString('hex');
     }
@@ -309,4 +318,47 @@ public function hash($includeSignature=false)
 
         return $this->sha3($serializedTx);
     }
+
+    /**
+     * getFromAddress
+     * 
+     * @return string
+     */
+    public function getFromAddress()
+    {
+        $from = $this->offsetGet('from');
+
+        if ($from) {
+            var_dump(1);
+            return $from;
+        }
+        if (!isset($this->privateKey) || !($this->privateKey instanceof KeyPair)) {
+            // recover from hash
+            $r = $this->offsetGet('r');
+            $s = $this->offsetGet('s');
+            $v = $this->offsetGet('v');
+            $chainId = $this->offsetGet('chainId');
+
+            if (!$r || !$s) {
+                throw new RuntimeException('Invalid signature r and s.');
+            }
+            $txHash = $this->hash(false);
+
+            if ($chainId && $chainId > 0) {
+                $v -= ($chainId * 2);
+            }
+            $v -= 35;
+            $publicKey = $this->secp256k1->recoverPubKey($txHash, [
+                'r' => $r,
+                's' => $s
+            ], $v);
+            $publicKey = $publicKey->encode('hex');
+        } else {
+            $publicKey = $this->privateKey->getPublic(false, 'hex');
+        }
+        $from = '0x' . substr($this->sha3(substr(hex2bin($publicKey), 1)), 24);
+
+        $this->offsetSet('from', $from);
+        return $from;
+    }
 }
\ No newline at end of file
diff --git a/test/unit/TransactionTest.php b/test/unit/TransactionTest.php
index f6f704f..9ad21f6 100644
--- a/test/unit/TransactionTest.php
+++ b/test/unit/TransactionTest.php
@@ -218,4 +218,65 @@ public function testEIP155()
         $this->assertEquals('daf5a779ae972f972197303d7b574746c7ef83eadac0f2791ad23db92e4c8e53', $transaction->hash(false));
         $this->assertEquals('f86c098504a817c800825208943535353535353535353535353535353535353535880de0b6b3a76400008025a028ef61340bd939bc2195fe537567866003e1a15d3c71ff63e1590620aa636276a067cbe9d8997f761aecb703304b3800ccf555c9f3dc64214b297fb1966a3b6d83', $transaction->sign('0x4646464646464646464646464646464646464646464646464646464646464646'));
     }
+
+    /**
+     * testGetFromAddress
+     * 0x9d8a62f656a8d1615c1294fd71e9cfb3e4855a4f
+     * 
+     * @return void
+     */
+    public function testGetFromAddress()
+    {
+        $transaction = new Transaction([
+            'nonce' => '0x09',
+            'to' => '0x3535353535353535353535353535353535353535',
+            'gas' => '0x5208',
+            'gasPrice' => '0x4a817c800',
+            'value' => '0xde0b6b3a7640000',
+            'chainId' => 1,
+            'data' => ''
+        ]);
+        // sign tx
+        $transaction->sign('0x4646464646464646464646464646464646464646464646464646464646464646');
+        $r = $transaction['r'];
+        $s = $transaction['s'];
+        $v = $transaction['v'];
+
+        // get from privatekey
+        $fromA = $transaction->getFromAddress();
+
+        $transaction = new Transaction([
+            'nonce' => '0x09',
+            'to' => '0x3535353535353535353535353535353535353535',
+            'gas' => '0x5208',
+            'gasPrice' => '0x4a817c800',
+            'value' => '0xde0b6b3a7640000',
+            'chainId' => 1,
+            'data' => ''
+        ]);
+        $transaction['r'] = $r;
+        $transaction['s'] = $s;
+        $transaction['v'] = $v;
+
+        // get from r, s, v
+        $fromB = $transaction->getFromAddress();
+
+        $transaction = new Transaction([
+            'from' => '0x9d8a62f656a8d1615c1294fd71e9cfb3e4855a4f',
+            'nonce' => '0x09',
+            'to' => '0x3535353535353535353535353535353535353535',
+            'gas' => '0x5208',
+            'gasPrice' => '0x4a817c800',
+            'value' => '0xde0b6b3a7640000',
+            'chainId' => 1,
+            'data' => ''
+        ]);
+
+        // get from transaction
+        $fromC = $transaction->getFromAddress();
+
+        $this->assertEquals('0x9d8a62f656a8d1615c1294fd71e9cfb3e4855a4f', $fromA);
+        $this->assertEquals($fromA, $fromB);
+        $this->assertEquals($fromB, $fromC);
+    }
 }
\ No newline at end of file