diff --git a/tests/test_abuse_prevention.py b/tests/test_abuse_prevention.py
index 8cd8ae9..5197627 100644
--- a/tests/test_abuse_prevention.py
+++ b/tests/test_abuse_prevention.py
@@ -226,6 +226,108 @@ class TestWindowReset:
             assert count == 1  # Counter reset
 
 
+class TestMinimumSizeEnforcement:
+    """Test minimum paste size requirement."""
+
+    @pytest.fixture
+    def minsize_app(self):
+        """Create app with minimum size requirement enabled."""
+        app = create_app("testing")
+        app.config["MIN_PASTE_SIZE"] = 64  # Require 64 bytes minimum
+        return app
+
+    @pytest.fixture
+    def minsize_client(self, minsize_app):
+        """Create test client with minimum size requirement."""
+        return minsize_app.test_client()
+
+    def test_small_content_rejected(self, minsize_client):
+        """Content below minimum size should be rejected."""
+        response = minsize_client.post("/", data=b"too small")
+        assert response.status_code == 400
+
+        data = response.get_json()
+        assert data["error"] == "Paste too small"
+        assert data["size"] == 9
+        assert data["min_size"] == 64
+        assert "hint" in data
+
+    def test_content_at_minimum_accepted(self, minsize_client):
+        """Content at minimum size should be accepted."""
+        content = b"x" * 64
+        response = minsize_client.post("/", data=content)
+        assert response.status_code == 201
+
+    def test_content_above_minimum_accepted(self, minsize_client):
+        """Content above minimum size should be accepted."""
+        content = b"x" * 128
+        response = minsize_client.post("/", data=content)
+        assert response.status_code == 201
+
+    def test_minsize_disabled_by_default(self, client):
+        """Minimum size check should be disabled by default (MIN_PASTE_SIZE=0)."""
+        response = client.post("/", data=b"x")
+        assert response.status_code == 201
+
+
+class TestBinaryRequirement:
+    """Test binary content requirement (MIME-based encryption enforcement)."""
+
+    @pytest.fixture
+    def binary_app(self):
+        """Create app with binary requirement enabled."""
+        app = create_app("testing")
+        app.config["REQUIRE_BINARY"] = True
+        return app
+
+    @pytest.fixture
+    def binary_client(self, binary_app):
+        """Create test client with binary requirement."""
+        return binary_app.test_client()
+
+    def test_plaintext_rejected(self, binary_client):
+        """UTF-8 text should be rejected when binary required."""
+        response = binary_client.post("/", data=b"Hello, this is plaintext")
+        assert response.status_code == 400
+
+        data = response.get_json()
+        assert data["error"] == "Recognizable format not allowed"
+        assert data["detected"] == "text/plain"
+        assert "hint" in data
+
+    def test_png_rejected(self, binary_client):
+        """PNG magic bytes should be rejected."""
+        # PNG signature: 89 50 4E 47 0D 0A 1A 0A
+        png_content = b"\x89PNG\r\n\x1a\n" + b"\x00" * 100
+        response = binary_client.post("/", data=png_content)
+        assert response.status_code == 400
+
+        data = response.get_json()
+        assert data["detected"] == "image/png"
+
+    def test_jpeg_rejected(self, binary_client):
+        """JPEG magic bytes should be rejected."""
+        jpeg_content = b"\xff\xd8\xff" + b"\x00" * 100
+        response = binary_client.post("/", data=jpeg_content)
+        assert response.status_code == 400
+
+        data = response.get_json()
+        assert data["detected"] == "image/jpeg"
+
+    def test_random_binary_accepted(self, binary_client):
+        """Random binary data (encrypted) should be accepted."""
+        import os
+
+        random_data = os.urandom(256)  # High entropy, no magic bytes
+        response = binary_client.post("/", data=random_data)
+        assert response.status_code == 201
+
+    def test_binary_disabled_by_default(self, client):
+        """Binary requirement should be disabled by default."""
+        response = client.post("/", data=b"plaintext is fine by default")
+        assert response.status_code == 201
+
+
 class TestEntropyEnforcement:
     """Test minimum entropy requirement."""