스마트폰 데이터베이스 환경에서 암호화된 데이터에 대한 효율적인 키워드검색 기법

Abstract

We are using our smartphone for our business as well as ours lives. Thus, user’s privacy data and a company secret arestored at smartphone. By the way, the saved data on smartphone database can be exposed to a malicous attacker when amalicous app is installed in the smartphone or a user lose his/her smartphone because all data are stored as form of plaintextin the database. To prevent this disclosure of personal information, we need a database encryption method. However, if adatabase is encrypted, it causes of declining the performance. For example, when we search specific data in condition withencrypted database, we should decrypt all data stored in the database or search sequentially the data we want with accompanyingoverhead[1]. In this paper, we propose an efficient and searchable encryption method using variable length bloom filter under limitedresource circumstances(e.g., a smartphone). We compare with existing searchable symmetric encryption. Also, we implementedthe proposed method in android smartphone and evaluated the performance the proposed method. As a result through theimplementation, We can confirm that our method has over a 50% improvement in the search speed compared to the simplesearch method about encrypted database and has over a 70% space saving compared to the method of fixed length bloom filterwith the same false positive rate.