diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 869955d8..5dad7ecf 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -9,29 +9,33 @@ on:
     branches:
       - master
 jobs:
-  run:
+  test:
     runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        php-version: ['8.2', '8.3', '8.4', '8.5']
     steps:
       - name: Checkout
-        uses: actions/checkout@v2
-      - name: Set up php 8.0
+        uses: actions/checkout@v4
+      - name: Set up PHP ${{ matrix.php-version }}
         uses: shivammathur/setup-php@v2
         with:
-          php-version: '8.0'
+          php-version: ${{ matrix.php-version }}
+          coverage: xdebug
       - name: 'Create env file'
         run: |
           touch ${{ github.workspace }}/tests/.env
           echo RAZORPAY_API_KEY=${{ secrets.RAZORPAY_API_KEY }} >> ${{ github.workspace }}/tests/.env
           echo RAZORPAY_API_SECRET=${{ secrets.RAZORPAY_API_SECRET }} >> ${{ github.workspace }}/tests/.env
-          cat ${{ github.workspace }}/tests/.env          
       - name: Install dependencies
         run: composer self-update && composer install && composer require vlucas/phpdotenv && composer dump-autoload
       - name: Run tests and collect coverage
-        run: vendor/bin/phpunit ./tests/CoverageTest.php --coverage-clover coverage.xml .
+        run: vendor/bin/phpunit ./tests/CoverageTest.php --coverage-clover coverage.xml
         env:
            RAZORPAY_API_KEY: ${{ secrets.RAZORPAY_API_KEY }}
            RAZORPAY_API_SECRET: ${{ secrets.RAZORPAY_API_SECRET }}
            RAZORPAY_PARTNER_API_KEY: ${{ secrets.RAZORPAY_PARTNER_API_KEY }}
            RAZORPAY_PARTNER_API_SECRET: ${{ secrets.RAZORPAY_PARTNER_API_SECRET }}
       - name: Upload coverage to Codecov
-        uses: codecov/codecov-action@v3
+        if: matrix.php-version == '8.5'
+        uses: codecov/codecov-action@v4
diff --git a/composer.json b/composer.json
index 2ce0f7dd..5a2aca83 100644
--- a/composer.json
+++ b/composer.json
@@ -23,13 +23,13 @@
     "homepage": "https://docs.razorpay.com",
     "license": "MIT",
     "require": {
-        "php": ">=7.3",
+        "php": ">=8.2",
         "rmccue/requests": "^2.0",
         "ext-json": "*"
     },
     "require-dev": {
-        "raveren/kint": "1.*",
-        "phpunit/phpunit": "^9"
+        "kint-php/kint": "^5.0",
+        "phpunit/phpunit": "^9.6"
     },
     "autoload": {
         "psr-4": {
diff --git a/tests/SignatureVerificationNegativeTest.php b/tests/SignatureVerificationNegativeTest.php
new file mode 100644
index 00000000..3f6361c8
--- /dev/null
+++ b/tests/SignatureVerificationNegativeTest.php
@@ -0,0 +1,120 @@
+<?php
+
+namespace Razorpay\Tests;
+
+use Razorpay\Api\Api;
+use Razorpay\Api\Errors\SignatureVerificationError;
+
+class SignatureVerificationNegativeTest extends TestCase
+{
+    private $webhookPayload = '{"event":"payment.authorized"}';
+    private $webhookSecret = 'test_webhook_secret';
+
+    public function setUp(): void
+    {
+        parent::setUp();
+    }
+
+    /**
+     * Test that empty signature is rejected
+     */
+    public function testEmptySignatureRejected()
+    {
+        $this->expectException(SignatureVerificationError::class);
+
+        $this->api->utility->verifyWebhookSignature(
+            $this->webhookPayload,
+            '',
+            $this->webhookSecret
+        );
+    }
+
+    /**
+     * Test that wrong length signature is rejected
+     */
+    public function testWrongLengthSignatureRejected()
+    {
+        $this->expectException(SignatureVerificationError::class);
+
+        $this->api->utility->verifyWebhookSignature(
+            $this->webhookPayload,
+            'abc123',
+            $this->webhookSecret
+        );
+    }
+
+    /**
+     * Test that wrong value signature is rejected
+     * (rejected because value doesn't match, not because SDK validates hex format)
+     */
+    public function testWrongValueSignatureRejected()
+    {
+        $this->expectException(SignatureVerificationError::class);
+
+        $wrongSig = str_repeat('z', 64);
+        $this->api->utility->verifyWebhookSignature(
+            $this->webhookPayload,
+            $wrongSig,
+            $this->webhookSecret
+        );
+    }
+
+    /**
+     * Test that tampered valid-length hex signature is rejected
+     */
+    public function testTamperedValidHexSignatureRejected()
+    {
+        $this->expectException(SignatureVerificationError::class);
+
+        $tamperedSig = str_repeat('a', 64);
+        $this->api->utility->verifyWebhookSignature(
+            $this->webhookPayload,
+            $tamperedSig,
+            $this->webhookSecret
+        );
+    }
+
+    /**
+     * Test that dynamically generated valid signature is accepted
+     */
+    public function testValidDynamicSignatureAccepted()
+    {
+        $validSig = hash_hmac('sha256', $this->webhookPayload, $this->webhookSecret);
+
+        $this->assertNull($this->api->utility->verifyWebhookSignature(
+            $this->webhookPayload,
+            $validSig,
+            $this->webhookSecret
+        ));
+    }
+
+    /**
+     * Test signature verification with special characters in payload
+     */
+    public function testSpecialCharsInPayload()
+    {
+        $specialPayload = '{"event":"payment","data":{"notes":"Test & <script>alert(1)</script>"}}';
+        $validSig = hash_hmac('sha256', $specialPayload, $this->webhookSecret);
+
+        $this->assertNull($this->api->utility->verifyWebhookSignature(
+            $specialPayload,
+            $validSig,
+            $this->webhookSecret
+        ));
+    }
+
+    /**
+     * Test signature verification with unicode in payload
+     */
+    public function testUnicodeInPayload()
+    {
+        $unicodePayload = '{"event":"payment","data":{"name":"日本語テスト"}}';
+        $validSig = hash_hmac('sha256', $unicodePayload, $this->webhookSecret);
+
+        $this->assertNull($this->api->utility->verifyWebhookSignature(
+            $unicodePayload,
+            $validSig,
+            $this->webhookSecret
+        ));
+    }
+}