Dictionary Attacks based on TDOA Using a Smartphone

Recent years, side channel attack has received more and more attention from security researchers because of its unexpected and unpredictable characteristics. Recovering the keystrokes using keyboard acoustic emanation is one of the most popular research. However, Prior attacks often rely on specialized equipments, complex deployment environments or extensive data, which limits their usage scenarios. To solve these problems, we propose a method to obtain the relative position of keys by Time Difference of Arrival (TDoA) method and then recover the words using a dictionary. This attack only uses one phone and does not require any training. Results show that our attack has a 45.2% success rate of finding the correct words in the TOP50 candidates over all the words we tested. For words with more than 10 letters, it has a 46.3% success rate of finding the correct words in the TOP 25 candidates.