Three ways to use AI on Android: The Good, the Bad and the Ugly

Session at Android Makers 2024:

Artificial Intelligence is revolutionizing the world, more and more apps are integrating AI, but are we doing it the right way?

In this talk, I will explore practical strategies for using AI responsibly in your Android apps. We will start with the “Ugly”, by showcasing a basic implementation and exploring the consequences. We will move forwards by improving our strategy but exposing the “Bad” pitfalls and leaks we could face. To finish, I will walk you through the “Good” strategy to craft secure prompts, leakproof API keys, and build robust architectures for cost-optimized AI integration in your Android apps.

Check my latest app at https://namewith.ai

Transcript

1. Three ways to use AI on Android Marcel Pintó Biescas - Android Dev and Indie-Maker The Good, the Bad and the Ugly
3. What is Generative AI then?
4. What is Generative AI then? Generative AI
5. What is Generative AI then? Generative AI Foundation Models Not limited to language tasks (image recognition, sound processing, etc…)
6. What is Generative AI then? Generative AI Foundation Models Large Language Models (LLM) Not limited to language tasks (image recognition, sound processing, etc…) GPT 3.5 / 4, LLaMa, Mistral, etc…
7. What is Generative AI then? Generative AI Foundation Models Large Language Models (LLM) ChatGPT Gemini … Not limited to language tasks (image recognition, sound processing, etc…) GPT 3.5 / 4, LLaMa, Mistral, etc… User interface, chatbots
8. Let’s use AI!
9. Peak of Inflated Expectations Innovation Trigger Trough of Disillusionment Plateau of Productivity Slope of Enlightenm ent Let’s use AI! Time Expectations
10. I have an idea!
11. Hey, how are you? I have an idea!
12. • Share text with the app Hey, how are you? I have an idea!
13. • Share text with the app • Create a reply Hey, how are you? I have an idea!
14. • Share text with the app • Create a reply • Copy to clipboard Hey, how are you? I have an idea!
15. • Share text with the app • Create a reply • Copy to clipboard • I will make millions! Hey, how are you? I have an idea!
16. Let’s check the docs Using Gemini SDK
17. Let’s check the docs 1. Get the API Key (easy!) Using Gemini SDK
18. Let’s check the docs 1. Get the API Key (easy!) 2. Secure API key Using Gemini SDK
19. Let’s check the docs 1. Get the API Key (easy!) 2. Secure API key Hardcode Key Using Gemini SDK
20. Let’s check the docs 1. Get the API Key (easy!) 2. Secure API key Hardcode Key Using Gemini SDK 3. Create Client
21. Let’s check the docs 1. Get the API Key (easy!) 2. Secure API key Hardcode Key Using Gemini SDK 3. Create Client 4. Generate response
22. @Composable fun ShareScreen(sourceText: String) { val context = LocalContext.current val clipboardManager = remember { context.getSystemService<ClipboardManager>()!! } val gemini = remember { GenerativeModel( modelName = "gemini-pro", apiKey = BuildConfig.apiKey ) } var result by remember { mutableStateOf("") } LaunchedEffect(Unit) { try { val prompt = "Create a funny reply for the given text: $sourceText"
23. } val gemini = remember { GenerativeModel( modelName = "gemini-pro", apiKey = BuildConfig.apiKey ) } var result by remember { mutableStateOf("") } LaunchedEffect(Unit) { try { val prompt = "Create a funny reply for the given text: $sourceText" result = gemini.generateContent(prompt).text!! clipboardManager.setPrimaryClip( ClipData.newPlainText("result", result) ) } catch (e: Exception) { result = "Something went wrong" e.printStackTrace() } } // ... }
24. } val gemini = remember { GenerativeModel( modelName = "gemini-pro", apiKey = BuildConfig.apiKey ) } var result by remember { mutableStateOf("") } LaunchedEffect(Unit) { try { val prompt = "Create a funny reply for the given text: $sourceText" result = gemini.generateContent(prompt).text!! clipboardManager.setPrimaryClip( ClipData.newPlainText("result", result) ) } catch (e: Exception) { result = "Something went wrong" e.printStackTrace() } } // ... }
25. } val gemini = remember { GenerativeModel( modelName = "gemini-pro", apiKey = BuildConfig.apiKey ) } var result by remember { mutableStateOf("") } LaunchedEffect(Unit) { try { val prompt = "Create a funny reply for the given text: $sourceText" result = gemini.generateContent(prompt).text!! clipboardManager.setPrimaryClip( ClipData.newPlainText("result", result) ) } catch (e: Exception) { result = "Something went wrong" e.printStackTrace() } } // ... }
26. MVP is ready! 1. Share any text with the app 2. Generate an answer 3. Copy to the clipboard 4. Reply!
27. MVP is ready! 1. Share any text with the app 2. Generate an answer 3. Copy to the clipboard 4. Reply!
28. Let’s Ship it!
30. Next day… 15/04 16/04 17/04 18/04
31. Next day… 15/04 16/04 17/04 18/04 $0.5 $1.2 $1200
32. What happened?
33. What happened? API Key was stolen!
34. What happened? • Download APK API Key was stolen!
35. What happened? • Download APK • Use Android Studio (or others) API Key was stolen!
36. What happened? • Download APK • Use Android Studio (or others) • Analyse the APK • Key is right there! API Key was stolen!
37. THE BAD
38. Let’s improve this!
39. Let’s improve this! Obfuscation
40. Let’s improve this! Obfuscation • R8 & ProGuard
41. Let’s improve this! Obfuscation • R8 & ProGuard • Base64 or custom logic
42. Let’s improve this! Obfuscation • R8 & ProGuard • Base64 or custom logic • Native code
43. Let’s improve this! Obfuscation • R8 & ProGuard • Base64 or custom logic • Native code • DexGuard
44. Let’s improve this! Obfuscation Encryption
45. Let’s improve this! Obfuscation Encryption Remote
46. Let’s Ship it!
47. Next day… 17/04 18/04 19/04 20/04
48. Next day… 17/04 18/04 19/04 20/04 $1200 $0.1 $1800
49. THE BAD
50. THE BAD THE UGLY
51. What happened?
52. What happened? API Key was stolen! again…
53. What happened? API Key was stolen! again… Get Public Key Get Encrypted Key Locally decrypt API Key
54. Let’s improve this! Obfuscation Encryption Remote
55. Let’s improve this! Authentication Obfuscation Encryption Remote
56. Flow
57. Flow 1. Encrypt API Key
58. Flow 1. Encrypt API Key 2. Obfuscate public key in code
59. Flow 1. Encrypt API Key 2. Obfuscate public key in code 3. Authenticate app/user
60. Flow 1. Encrypt API Key 2. Obfuscate public key in code 3. Authenticate app/user 4. Return encrypted API Key
61. Flow 1. Encrypt API Key 2. Obfuscate public key in code 3. Authenticate app/user 4. Return encrypted API Key 5. Decrypt with Public Key
62. A way to do it R8 / ProGuard Jetpack security-crypto Firebase Authentication Firebase Remote Config or Firestore
63. There is still an issue…
64. There is still an issue…
65. There is still an issue…
66. There is still an issue…
67. Let’s use App Check
70. There is a better way! Proxy
71. There is a better way! Firebase Functions
72. Firebase.appCheck.installAppCheckProviderFactory( PlayIntegrityAppCheckProviderFactory.getInstance(), ) private suspend fun generateResponse(content: String): String { val result = Firebase.functions .getHttpsCallable("generate") .call(mapOf("content" to content)) .await() return result.data as String }
73. Firebase.appCheck.installAppCheckProviderFactory( PlayIntegrityAppCheckProviderFactory.getInstance(), ) private suspend fun generateResponse(content: String): String { val result = Firebase.functions .getHttpsCallable("generate") .call(mapOf("content" to content)) .await() return result.data as String }
74. rateResponse(content: String): String { e.functions e("generate") tent" to content)) s String
75. rateResponse(content: String): String { e.functions e("generate") tent" to content)) s String @https_fn.on_call(enforce_app_check=True) def generate(req: https_fn.CallableRequest) -> https_fn.Response: """Given a text, generate a response""" if req.auth is None: raise https_fn.HttpsError( code=https_fn.FunctionsErrorCode.UNAUTHENTICATED, message="User not found.", ) content = req.data.get("content") if not content: raise https_fn. HttpsError( code=https_fn.FunctionsErrorCode.INVALID_ARGUMENT, message="Missing content", ) return generate_response(content)
76. rateResponse(content: String): String { e.functions e("generate") tent" to content)) s String @https_fn.on_call(enforce_app_check=True) def generate(req: https_fn.CallableRequest) -> https_fn.Response: """Given a text, generate a response""" if req.auth is None: raise https_fn.HttpsError( code=https_fn.FunctionsErrorCode.UNAUTHENTICATED, message="User not found.", ) content = req.data.get("content") if not content: raise https_fn. HttpsError( code=https_fn.FunctionsErrorCode.INVALID_ARGUMENT, message="Missing content", ) return generate_response(content)
77. rateResponse(content: String): String { e.functions e("generate") tent" to content)) s String @https_fn.on_call(enforce_app_check=True) def generate(req: https_fn.CallableRequest) -> https_fn.Response: """Given a text, generate a response""" if req.auth is None: raise https_fn.HttpsError( code=https_fn.FunctionsErrorCode.UNAUTHENTICATED, message="User not found.", ) content = req.data.get("content") if not content: raise https_fn. HttpsError( code=https_fn.FunctionsErrorCode.INVALID_ARGUMENT, message="Missing content", ) return generate_response(content)
78. @https_fn.on_call(enforce_app_check=True) def generate(req: https_fn.CallableRequest) -> https_fn.Response: """Given a text, generate a response""" if req.auth is None: raise https_fn.HttpsError( code=https_fn.FunctionsErrorCode.UNAUTHENTICATED, message="User not found.", ) content = req.data.get("content") if not content: raise https_fn. HttpsError( code=https_fn.FunctionsErrorCode.INVALID_ARGUMENT, message="Missing content", ) return generate_response(content)
79. @https_fn.on_call(enforce_app_check=True) def generate(req: https_fn.CallableRequest) -> https_fn.Response: """Given a text, generate a response""" if req.auth is None: raise https_fn.HttpsError( code=https_fn.FunctionsErrorCode.UNAUTHENTICATED, message="User not found.", ) content = req.data.get("content") if not content: raise https_fn. HttpsError( code=https_fn.FunctionsErrorCode.INVALID_ARGUMENT, message="Missing content", ) return generate_response(content)
80. @https_fn.on_call(enforce_app_check=True) def generate(req: https_fn.CallableRequest) -> https_fn.Response: """Given a text, generate a response""" if req.auth is None: raise https_fn.HttpsError( code=https_fn.FunctionsErrorCode.UNAUTHENTICATED, message="User not found.", ) content = req.data.get("content") if not content: raise https_fn. HttpsError( code=https_fn.FunctionsErrorCode.INVALID_ARGUMENT, message="Missing content", ) return generate_response(content)
81. @https_fn.on_call(enforce_app_check=True) def generate(req: https_fn.CallableRequest) -> https_fn.Response: """Given a text, generate a response""" if req.auth is None: raise https_fn.HttpsError( code=https_fn.FunctionsErrorCode.UNAUTHENTICATED, message="User not found.", ) content = req.data.get("content") if not content: raise https_fn. HttpsError( code=https_fn.FunctionsErrorCode.INVALID_ARGUMENT, message="Missing content", ) return generate_response(content)
82. @https_fn.on_call(enforce_app_check=True) def generate(req: https_fn.CallableRequest) -> https_fn.Response: """Given a text, generate a response""" if req.auth is None: raise https_fn.HttpsError( code=https_fn.FunctionsErrorCode.UNAUTHENTICATED, message="User not found.", ) content = req.data.get("content") if not content: raise https_fn. HttpsError( code=https_fn.FunctionsErrorCode.INVALID_ARGUMENT, message="Missing content", ) return generate_response(content)
83. private suspend fun generateResponse(content: String): String { val result = Firebase.functions .getHttpsCallable("generate") .call(mapOf("content" to content)) .await() return result.data as String } @https_fn.on_call(enforce_app_check=T def generate(req: https_fn.CallableRe """Given a text, generate a respo if req.auth is None: raise https_fn.HttpsError( code=https_fn.FunctionsEr message="User not found." ) content = req.data.get("content") if not content: raise https_fn. HttpsError( code=https_fn.FunctionsEr message="Missing content" ) return generate_response(content)
84. private suspend fun generateResponse(content: String): String { val result = Firebase.functions .getHttpsCallable("generate") .call(mapOf("content" to content)) .await() return result.data as String } @https_fn.on_call(enforce_app_check=T def generate(req: https_fn.CallableRe """Given a text, generate a respo if req.auth is None: raise https_fn.HttpsError( code=https_fn.FunctionsEr message="User not found." ) content = req.data.get("content") if not content: raise https_fn. HttpsError( code=https_fn.FunctionsEr message="Missing content" ) return generate_response(content)
85. Let’s Ship it!
86. Next day… 20/04 21/04 22/04 23/04 24/04 25/04
87. Next day… 20/04 21/04 22/04 23/04 24/04 25/04
88. THE BAD THE UGLY
89. THE GOOD THE BAD THE UGLY
90. THE GOOD THE UGLY THE BAD
91. THE GOOD THE UGLY THE BAD As Proxy
92. THE GOOD THE UGLY THE BAD
93. THE GOOD THE UGLY THE BAD • Key never in the client • Avoids unauthorised usage • Change prompts easily • Server side logic
94. THE GOOD THE UGLY THE BAD • Key never in the client • Avoids unauthorised usage • Change prompts easily • Server side logic • Increased time • More costly • Hard to implement streaming AI response
95. THE GOOD THE UGLY THE BAD • Key never in the client • Avoids unauthorised usage • Change prompts easily • Server side logic • Increased time • More costly • Hard to implement streaming AI response • Super easy to implement • Direct communication • Easy to hack • Hard to update API Key
96. THE GOOD THE UGLY THE BAD • Key never in the client • Avoids unauthorised usage • Change prompts easily • Server side logic • Increased time • More costly • Hard to implement streaming AI response • Super easy to implement • Direct communication • Easy to hack • Hard to update API Key • Direct communication • Fairly secure (for starting) • Easy to update API Key • Increase of cost • Slightly complex to implement • Harder to hack but possible
97. Some recommendations…
98. Some recommendations… • Always use App Check or similar mechanism
99. Some recommendations… • Always use App Check or similar mechanism • Do not store the key in Version control
100. Some recommendations… • Always use App Check or similar mechanism • Do not store the key in Version control • Use key management service
101. Some recommendations… • Always use App Check or similar mechanism • Do not store the key in Version control • Use key management service • Prefer Proxy-server to local keys
102. Some recommendations… • Always use App Check or similar mechanism • Do not store the key in Version control • Use key management service • Prefer Proxy-server to local keys • Do not store unencrypted key in device storage
103. Some recommendations… • Always use App Check or similar mechanism • Do not store the key in Version control • Use key management service • Prefer Proxy-server to local keys • Do not store unencrypted key in device storage • Import encrypted keys into secure hardware (e.g KeyStore)
104. Some recommendations… • Always use App Check or similar mechanism • Do not store the key in Version control • Use key management service • Prefer Proxy-server to local keys • Do not store unencrypted key in device storage • Import encrypted keys into secure hardware (e.g KeyStore) • Set hard-limits to your API when possible.
105. Security last words THE GOOD THE UGLY THE BAD "There's no silver bullet"
106. Security last words THE GOOD THE UGLY THE BAD HARD NOT so EASY EASY "There's no silver bullet"
107. Thank you Follow me: @marxallski Latest app: https://namewith.ai