diff --git a/app/src/main/java/org/matrix/demo/KeyStoreTestRunner.kt b/app/src/main/java/org/matrix/demo/KeyStoreTestRunner.kt
new file mode 100644
index 0000000..536cf4f
--- /dev/null
+++ b/app/src/main/java/org/matrix/demo/KeyStoreTestRunner.kt
@@ -0,0 +1,275 @@
+package org.matrix.demo
+
+import android.security.keystore.KeyGenParameterSpec
+import android.security.keystore.KeyProperties
+import android.util.Log
+import java.nio.charset.StandardCharsets
+import java.security.KeyPair
+import java.security.KeyPairGenerator
+import java.security.KeyStore
+import java.security.Signature
+import javax.crypto.Cipher
+
+/**
+ * A comprehensive test runner for Android Keystore cryptographic operations.
+ * This class is designed to test the functionality of a TEE simulator by executing
+ * a suite of standard signing and encryption operations.
+ */
+class KeyStoreTestRunner {
+
+    companion object {
+        private const val TAG = "Demo"
+        private const val ANDROID_KEYSTORE = "AndroidKeyStore"
+
+        // Use distinct aliases for each test to ensure they are isolated.
+        private const val EC_KEY_ALIAS = "org.matrix.demo.ec_test_key"
+        private const val RSA_SIGN_KEY_ALIAS = "org.matrix.demo.rsa_sign_test_key"
+        private const val RSA_ENCRYPT_KEY_ALIAS = "org.matrix.demo.rsa_encrypt_test_key"
+        private const val NON_EXISTENT_KEY_ALIAS = "org.matrix.demo.non_existent_key"
+        private val LARGE_KEY_ALIAS: String = "a".repeat(507 * 1024 + 269)
+    }
+
+    /**
+     * Executes the full suite of cryptographic tests and logs a final summary.
+     */
+    fun runAllTests() {
+        Log.d(TAG, "=============================================")
+        Log.d(TAG, "      Starting Keystore Test Suite")
+        Log.d(TAG, "=============================================")
+
+        val results = linkedMapOf<String, Boolean>()
+
+        results["EC Sign & Verify"] = testEcSignAndVerify()
+        results["RSA Sign & Verify"] = testRsaSignAndVerify()
+        results["RSA Encrypt & Decrypt"] = testRsaEncryptAndDecrypt()
+        results["Get Non-Existent Key"] = testGetNonExistentKey()
+        results["Generation with Large Alias"] = testLargeAliasGeneration()
+
+        Log.d(TAG, "=============================================")
+        Log.d(TAG, "               Test Summary")
+        Log.d(TAG, "---------------------------------------------")
+        results.forEach { (testName, result) ->
+            val resultString = if (result) "PASSED" else "FAILED"
+            Log.d(TAG, "${testName.padEnd(25)} | $resultString")
+        }
+        Log.d(TAG, "=============================================")
+    }
+
+    /**
+     * Tests the generation, signing, and verification of an ECDSA key pair.
+     * @return `true` if all steps succeed, `false` otherwise.
+     */
+    fun testEcSignAndVerify(): Boolean {
+        Log.d(TAG, "--- Starting Test: EC Sign & Verify ---")
+        try {
+            val spec = KeyGenParameterSpec.Builder(
+                EC_KEY_ALIAS,
+                KeyProperties.PURPOSE_SIGN or KeyProperties.PURPOSE_VERIFY
+            ).setDigests(KeyProperties.DIGEST_SHA256).build()
+
+            val keyPair = generateKeyPair(KeyProperties.KEY_ALGORITHM_EC, spec) ?: return false
+            Log.i(TAG, "EC KeyPair generated successfully.")
+
+            val data = "test data for ec signing".toByteArray(StandardCharsets.UTF_8)
+            val signature = Signature.getInstance("SHA256withECDSA")
+
+            // Sign the data
+            signature.initSign(keyPair.private)
+            signature.update(data)
+            val signatureBytes = signature.sign()
+            Log.i(TAG, "Data signed with EC key.")
+
+            // Verify the signature
+            signature.initVerify(keyPair.public)
+            signature.update(data)
+            if (!signature.verify(signatureBytes)) {
+                Log.e(TAG, "EC signature verification FAILED.")
+                return false
+            }
+            Log.i(TAG, "EC signature verification PASSED.")
+            return true
+        } catch (e: Exception) {
+            Log.e(TAG, "EC test failed with exception.", e)
+            return false
+        } finally {
+            deleteKey(EC_KEY_ALIAS)
+            Log.d(TAG, "--- Finished Test: EC Sign & Verify ---\n")
+        }
+    }
+
+    /**
+     * Tests the generation with a large key alias.
+     * @return `true` if all steps succeed, `false` otherwise.
+     */
+    fun testLargeAliasGeneration(): Boolean {
+        Log.d(TAG, "--- Starting Test: Generation with Large Alias ---")
+        try {
+            val spec = KeyGenParameterSpec.Builder(
+                LARGE_KEY_ALIAS,
+                KeyProperties.PURPOSE_SIGN or KeyProperties.PURPOSE_VERIFY
+            ).setDigests(KeyProperties.DIGEST_SHA256).build()
+
+            val keyPair = generateKeyPair(KeyProperties.KEY_ALGORITHM_EC, spec) ?: return false
+            Log.i(TAG, "EC KeyPair generated with large alias successfully.")
+            return true
+        } catch (e: Exception) {
+            Log.e(TAG, "Generation test with large alias failed with exception.", e)
+            return false
+        } finally {
+            deleteKey(LARGE_KEY_ALIAS)
+            Log.d(TAG, "--- Finished Test: Generation with Large Alias ---\n")
+        }
+    }
+
+    /**
+     * Tests the generation, signing, and verification of an RSA key pair.
+     * @return `true` if all steps succeed, `false` otherwise.
+     */
+    fun testRsaSignAndVerify(): Boolean {
+        Log.d(TAG, "--- Starting Test: RSA Sign & Verify ---")
+        try {
+            val spec = KeyGenParameterSpec.Builder(
+                RSA_SIGN_KEY_ALIAS,
+                KeyProperties.PURPOSE_SIGN or KeyProperties.PURPOSE_VERIFY
+            ).run {
+                setDigests(KeyProperties.DIGEST_SHA256)
+                setSignaturePaddings(KeyProperties.SIGNATURE_PADDING_RSA_PKCS1)
+                build()
+            }
+
+            val keyPair = generateKeyPair(KeyProperties.KEY_ALGORITHM_RSA, spec) ?: return false
+            Log.i(TAG, "RSA Signing KeyPair generated successfully.")
+
+            val data = "test data for rsa signing".toByteArray(StandardCharsets.UTF_8)
+            val signature = Signature.getInstance("SHA256withRSA")
+
+            signature.initSign(keyPair.private)
+            signature.update(data)
+            val signatureBytes = signature.sign()
+            Log.i(TAG, "Data signed with RSA key.")
+
+            signature.initVerify(keyPair.public)
+            signature.update(data)
+            if (!signature.verify(signatureBytes)) {
+                Log.e(TAG, "RSA signature verification FAILED.")
+                return false
+            }
+            Log.i(TAG, "RSA signature verification PASSED.")
+            return true
+        } catch (e: Exception) {
+            Log.e(TAG, "RSA signing test failed with exception.", e)
+            return false
+        } finally {
+            deleteKey(RSA_SIGN_KEY_ALIAS)
+            Log.d(TAG, "--- Finished Test: RSA Sign & Verify ---\n")
+        }
+    }
+
+    /**
+     * Tests the generation, encryption, and decryption of an RSA key pair.
+     * @return `true` if all steps succeed, `false` otherwise.
+     */
+    fun testRsaEncryptAndDecrypt(): Boolean {
+        Log.d(TAG, "--- Starting Test: RSA Encrypt & Decrypt ---")
+        try {
+            val spec = KeyGenParameterSpec.Builder(
+                RSA_ENCRYPT_KEY_ALIAS,
+                KeyProperties.PURPOSE_ENCRYPT or KeyProperties.PURPOSE_DECRYPT
+            ).run {
+                setBlockModes(KeyProperties.BLOCK_MODE_ECB)
+                setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_RSA_PKCS1)
+                build()
+            }
+
+            val keyPair = generateKeyPair(KeyProperties.KEY_ALGORITHM_RSA, spec) ?: return false
+            Log.i(TAG, "RSA Encryption KeyPair generated successfully.")
+
+            val originalData = "test data for rsa encryption".toByteArray(StandardCharsets.UTF_8)
+            val cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding")
+
+            // Encrypt
+            cipher.init(Cipher.ENCRYPT_MODE, keyPair.public)
+            val encryptedData = cipher.doFinal(originalData)
+            Log.i(TAG, "Data encrypted with RSA key.")
+
+            // Decrypt
+            cipher.init(Cipher.DECRYPT_MODE, keyPair.private)
+            val decryptedData = cipher.doFinal(encryptedData)
+            Log.i(TAG, "Data decrypted with RSA key.")
+
+            if (!originalData.contentEquals(decryptedData)) {
+                Log.e(TAG, "Decrypted data does not match original data. FAILED.")
+                return false
+            }
+            Log.i(TAG, "Decrypted data matches original. PASSED.")
+            return true
+        } catch (e: Exception) {
+            Log.e(TAG, "RSA encryption test failed with exception.", e)
+            return false
+        } finally {
+            deleteKey(RSA_ENCRYPT_KEY_ALIAS)
+            Log.d(TAG, "--- Finished Test: RSA Encrypt & Decrypt ---\n")
+        }
+    }
+
+    /**
+     * Tests that attempting to retrieve a non-existent key correctly returns null.
+     * @return `true` if the key is not found as expected, `false` otherwise.
+     */
+    fun testGetNonExistentKey(): Boolean {
+        Log.d(TAG, "--- Starting Test: Get Non-Existent Key ---")
+        var success = false
+        try {
+            // First, ensure the key does not exist from a previous failed run.
+            deleteKey(NON_EXISTENT_KEY_ALIAS)
+
+            val keyStore = KeyStore.getInstance(ANDROID_KEYSTORE).apply { load(null) }
+            val key = keyStore.getKey(NON_EXISTENT_KEY_ALIAS, null)
+
+            if (key == null) {
+                Log.i(TAG, "getKey correctly returned null for a non-existent alias. PASSED.")
+                success = true
+            } else {
+                Log.e(TAG, "getKey unexpectedly returned a key for a non-existent alias. FAILED.")
+                success = false
+            }
+        } catch (e: Exception) {
+            Log.e(TAG, "Get non-existent key test failed with exception.", e)
+            success = false
+        } finally {
+            Log.d(TAG, "--- Finished Test: Get Non-Existent Key ---\n")
+        }
+        return success
+    }
+
+    /**
+     * A generic helper to generate a KeyPair in the Android Keystore using a given spec.
+     * It deletes any pre-existing key with the same alias.
+     */
+    private fun generateKeyPair(algorithm: String, spec: KeyGenParameterSpec): KeyPair? {
+        return try {
+            deleteKey(spec.keystoreAlias)
+            KeyPairGenerator.getInstance(algorithm, ANDROID_KEYSTORE).apply {
+                initialize(spec)
+            }.generateKeyPair()
+        } catch (e: Exception) {
+            Log.e(TAG, "KeyPair generation failed for alias: ${spec.keystoreAlias}", e)
+            null
+        }
+    }
+
+    /**
+     * A helper to safely delete a key from the Android Keystore.
+     */
+    private fun deleteKey(alias: String) {
+        try {
+            val keyStore = KeyStore.getInstance(ANDROID_KEYSTORE).apply { load(null) }
+            if (keyStore.containsAlias(alias)) {
+                keyStore.deleteEntry(alias)
+                Log.d(TAG, "Cleaned up existing key with alias: $alias")
+            }
+        } catch (e: Exception) {
+            Log.e(TAG, "Failed to delete key: $alias", e)
+        }
+    }
+}
diff --git a/app/src/main/java/org/matrix/demo/MainActivity.kt b/app/src/main/java/org/matrix/demo/MainActivity.kt
index 8d09bb6..2883acb 100644
--- a/app/src/main/java/org/matrix/demo/MainActivity.kt
+++ b/app/src/main/java/org/matrix/demo/MainActivity.kt
@@ -41,6 +41,8 @@ class MainActivity : AppCompatActivity() {
                 }, 200) // Double click time window
             }
         }
+
+         KeyStoreTestRunner().runAllTests()
     }
 
     /**