diff --git a/src/Strategy/PublicCacheStrategy.php b/src/Strategy/PublicCacheStrategy.php
index 411dda1..668502d 100644
--- a/src/Strategy/PublicCacheStrategy.php
+++ b/src/Strategy/PublicCacheStrategy.php
@@ -37,6 +37,18 @@ protected function getCacheObject(RequestInterface $request, ResponseInterface $
             return;
         }
 
+        // RFC 9111 Section 3.5: Check Authorization header caching restrictions for shared caches
+        if ($request->hasHeader('Authorization')) {
+            // Requests with Authorization header should only be cached if response contains
+            // one of the following directives: public, must-revalidate, s-maxage
+            if (!$cacheControl->has('public') 
+                && !$cacheControl->has('must-revalidate') 
+                && !$cacheControl->has('s-maxage')) {
+                // No explicit authorization to cache authenticated requests
+                return;
+            }
+        }
+
         return parent::getCacheObject($request, $response);
     }
 }
diff --git a/tests/AuthorizationCacheTest.php b/tests/AuthorizationCacheTest.php
new file mode 100644
index 0000000..14e6faa
--- /dev/null
+++ b/tests/AuthorizationCacheTest.php
@@ -0,0 +1,263 @@
+<?php
+
+namespace Kevinrob\GuzzleCache\Tests;
+
+use GuzzleHttp\Psr7\Request;
+use GuzzleHttp\Psr7\Response;
+use Kevinrob\GuzzleCache\Storage\VolatileRuntimeStorage;
+use Kevinrob\GuzzleCache\Strategy\PrivateCacheStrategy;
+use Kevinrob\GuzzleCache\Strategy\PublicCacheStrategy;
+use PHPUnit\Framework\TestCase;
+
+class AuthorizationCacheTest extends TestCase
+{
+    /**
+     * Test that requests with Authorization header are NOT cached when response only has max-age
+     */
+    public function testAuthorizationHeaderNotCachedWithMaxAge()
+    {
+        $storage = new VolatileRuntimeStorage();
+        $strategy = new PublicCacheStrategy($storage);
+
+        $request = new Request('GET', 'https://api.example.com/data', [
+            'Authorization' => 'Bearer secret-token'
+        ]);
+        
+        $response = new Response(200, [
+            'Cache-Control' => 'max-age=3600'
+        ], 'Private data');
+
+        $result = $strategy->cache($request, $response);
+        $this->assertFalse($result, 'Request with Authorization header should not be cached with only max-age');
+
+        $cached = $strategy->fetch($request);
+        $this->assertNull($cached, 'No cache entry should exist for authorized request with only max-age');
+    }
+
+    /**
+     * Test that requests with Authorization header ARE cached when response has Cache-Control: public
+     */
+    public function testAuthorizationHeaderCachedWithPublic()
+    {
+        $storage = new VolatileRuntimeStorage();
+        $strategy = new PublicCacheStrategy($storage);
+
+        $request = new Request('GET', 'https://api.example.com/data', [
+            'Authorization' => 'Bearer secret-token'
+        ]);
+        
+        $response = new Response(200, [
+            'Cache-Control' => 'public, max-age=3600'
+        ], 'Public data');
+
+        $result = $strategy->cache($request, $response);
+        $this->assertTrue($result, 'Request with Authorization header should be cached with public directive');
+
+        $cached = $strategy->fetch($request);
+        $this->assertNotNull($cached, 'Cache entry should exist for authorized request with public directive');
+        $this->assertEquals('Public data', (string) $cached->getResponse()->getBody());
+    }
+
+    /**
+     * Test that requests with Authorization header ARE cached when response has Cache-Control: must-revalidate
+     */
+    public function testAuthorizationHeaderCachedWithMustRevalidate()
+    {
+        $storage = new VolatileRuntimeStorage();
+        $strategy = new PublicCacheStrategy($storage);
+
+        $request = new Request('GET', 'https://api.example.com/data', [
+            'Authorization' => 'Bearer secret-token'
+        ]);
+        
+        $response = new Response(200, [
+            'Cache-Control' => 'must-revalidate, max-age=3600'
+        ], 'Revalidate data');
+
+        $result = $strategy->cache($request, $response);
+        $this->assertTrue($result, 'Request with Authorization header should be cached with must-revalidate directive');
+
+        $cached = $strategy->fetch($request);
+        $this->assertNotNull($cached, 'Cache entry should exist for authorized request with must-revalidate directive');
+        $this->assertEquals('Revalidate data', (string) $cached->getResponse()->getBody());
+    }
+
+    /**
+     * Test that requests with Authorization header ARE cached when response has Cache-Control: s-maxage
+     */
+    public function testAuthorizationHeaderCachedWithSMaxage()
+    {
+        $storage = new VolatileRuntimeStorage();
+        $strategy = new PublicCacheStrategy($storage);
+
+        $request = new Request('GET', 'https://api.example.com/data', [
+            'Authorization' => 'Bearer secret-token'
+        ]);
+        
+        $response = new Response(200, [
+            'Cache-Control' => 's-maxage=1800, max-age=3600'
+        ], 'Shared cache data');
+
+        $result = $strategy->cache($request, $response);
+        $this->assertTrue($result, 'Request with Authorization header should be cached with s-maxage directive');
+
+        $cached = $strategy->fetch($request);
+        $this->assertNotNull($cached, 'Cache entry should exist for authorized request with s-maxage directive');
+        $this->assertEquals('Shared cache data', (string) $cached->getResponse()->getBody());
+    }
+
+    /**
+     * Test that requests WITHOUT Authorization header are cached normally with max-age
+     */
+    public function testNoAuthorizationHeaderCachedWithMaxAge()
+    {
+        $storage = new VolatileRuntimeStorage();
+        $strategy = new PrivateCacheStrategy($storage);
+
+        $request = new Request('GET', 'https://api.example.com/data');
+        
+        $response = new Response(200, [
+            'Cache-Control' => 'max-age=3600'
+        ], 'Public data');
+
+        $result = $strategy->cache($request, $response);
+        $this->assertTrue($result, 'Request without Authorization header should be cached normally');
+
+        $cached = $strategy->fetch($request);
+        $this->assertNotNull($cached, 'Cache entry should exist for non-authorized request');
+        $this->assertEquals('Public data', (string) $cached->getResponse()->getBody());
+    }
+
+    /**
+     * Test PublicCacheStrategy behavior with Authorization headers
+     */
+    public function testPublicCacheStrategyWithAuthorization()
+    {
+        $storage = new VolatileRuntimeStorage();
+        $strategy = new PublicCacheStrategy($storage);
+
+        // Test that private cache with authorization is not cached in public strategy
+        $request = new Request('GET', 'https://api.example.com/data', [
+            'Authorization' => 'Bearer secret-token'
+        ]);
+        
+        $response = new Response(200, [
+            'Cache-Control' => 'private, max-age=3600'
+        ], 'Private data');
+
+        $result = $strategy->cache($request, $response);
+        $this->assertFalse($result, 'Private response should not be cached in public strategy');
+
+        // Test that public response with authorization is cached
+        $response2 = new Response(200, [
+            'Cache-Control' => 'public, max-age=3600'
+        ], 'Public data');
+
+        $result2 = $strategy->cache($request, $response2);
+        $this->assertTrue($result2, 'Public response with authorization should be cached in public strategy');
+
+        $cached = $strategy->fetch($request);
+        $this->assertNotNull($cached, 'Cache entry should exist for public authorized request');
+        $this->assertEquals('Public data', (string) $cached->getResponse()->getBody());
+    }
+
+    /**
+     * Test multiple allowed directives together
+     */
+    public function testMultipleAllowedDirectives()
+    {
+        $storage = new VolatileRuntimeStorage();
+        $strategy = new PublicCacheStrategy($storage);
+
+        $request = new Request('GET', 'https://api.example.com/data', [
+            'Authorization' => 'Bearer secret-token'
+        ]);
+        
+        $response = new Response(200, [
+            'Cache-Control' => 'public, must-revalidate, s-maxage=1800, max-age=3600'
+        ], 'Multi directive data');
+
+        $result = $strategy->cache($request, $response);
+        $this->assertTrue($result, 'Request with Authorization header should be cached with multiple allowed directives');
+
+        $cached = $strategy->fetch($request);
+        $this->assertNotNull($cached, 'Cache entry should exist for authorized request with multiple allowed directives');
+        $this->assertEquals('Multi directive data', (string) $cached->getResponse()->getBody());
+    }
+
+    /**
+     * Test case sensitivity of Authorization header
+     */
+    public function testAuthorizationHeaderCaseSensitivity()
+    {
+        $storage = new VolatileRuntimeStorage();
+        $strategy = new PublicCacheStrategy($storage);
+
+        $requests = [
+            new Request('GET', 'https://api.example.com/data', ['Authorization' => 'Bearer token']),
+            new Request('GET', 'https://api.example.com/data', ['authorization' => 'Bearer token']),
+            new Request('GET', 'https://api.example.com/data', ['AUTHORIZATION' => 'Bearer token']),
+        ];
+        
+        $response = new Response(200, [
+            'Cache-Control' => 'max-age=3600'
+        ], 'Test data');
+
+        foreach ($requests as $request) {
+            $result = $strategy->cache($request, $response);
+            $this->assertFalse($result, 'Authorization header should be detected regardless of case');
+
+            $cached = $strategy->fetch($request);
+            $this->assertNull($cached, 'No cache entry should exist for any case variation of Authorization header');
+        }
+    }
+
+    /**
+     * Test that other cache control directives still work as expected
+     */
+    public function testOtherCacheControlDirectivesStillWork()
+    {
+        $storage = new VolatileRuntimeStorage();
+        $strategy = new PublicCacheStrategy($storage);
+
+        // Test no-store still prevents caching even with authorization allowances
+        $request = new Request('GET', 'https://api.example.com/data', [
+            'Authorization' => 'Bearer secret-token'
+        ]);
+        
+        $response = new Response(200, [
+            'Cache-Control' => 'public, no-store, max-age=3600'
+        ], 'No store data');
+
+        $result = $strategy->cache($request, $response);
+        $this->assertFalse($result, 'no-store should still prevent caching even with public directive');
+
+        $cached = $strategy->fetch($request);
+        $this->assertNull($cached, 'No cache entry should exist when no-store is present');
+    }
+
+    /**
+     * Test that PrivateCacheStrategy still caches requests with Authorization header normally
+     */
+    public function testPrivateCacheStrategyAllowsAuthorizationCaching()
+    {
+        $storage = new VolatileRuntimeStorage();
+        $strategy = new PrivateCacheStrategy($storage);
+
+        $request = new Request('GET', 'https://api.example.com/data', [
+            'Authorization' => 'Bearer secret-token'
+        ]);
+        
+        // Private cache should cache this even with just max-age
+        $response = new Response(200, [
+            'Cache-Control' => 'max-age=3600'
+        ], 'Private cache data');
+
+        $result = $strategy->cache($request, $response);
+        $this->assertTrue($result, 'Private cache should allow caching of authenticated requests');
+
+        $cached = $strategy->fetch($request);
+        $this->assertNotNull($cached, 'Cache entry should exist in private cache for authenticated request');
+        $this->assertEquals('Private cache data', (string) $cached->getResponse()->getBody());
+    }
+}
\ No newline at end of file