Google DeepMind and Singapore build an on-device scam detector on Gemma

Google DeepMind and the Government Technology Agency of Singapore (GovTech) presented the model at Singapore International Cyber Week, under Google DeepMind’s National AI Partnership with the Singapore Government. Scams make up more than half of Singapore’s reported crimes, and social engineering, in which attackers win a victim’s trust in conversation before asking for money, accounts for up to 80% of losses.

Google DeepMind fine-tuned a lightweight Gemma model on local scam conversations, from impersonations of public institutions, banks and local figures to regional schemes, and optimised it for typical smartphones in Singapore. It runs on the phone because many messaging apps are end-to-end encrypted, so their servers can’t read the chats.

A classifier, a small model that sorts messages, screens each incoming one using little power. Suspicious or ambiguous messages go to the Gemma model, which reads more of the conversation and either raises a scam alert or clears it as a false alarm.

Fine-tuning ran in GovTech’s own Google Cloud environment, on anonymised scam reports and intelligence feeds rather than citizens’ data. Google DeepMind says messaging platforms and phone operating system makers can build the models into their products. It hasn’t named any that will, or said which Gemma version it used or how accurate the model is.