Pattern matching algorithms for encrypted non-static texts
Meng Zhang, Dequan Chen, Nan Li · International Journal of Wireless and Mobile Computing · 2017
We consider the problem of pattern matching on encrypted texts. In this problem, users transfer the encrypted text and patterns to a third party, and the third party searches for all the occurrences of the patterns in the encrypted text; the matching results are encrypted such that only some specified users can read. The third party cannot access all the plain texts including the pattern, the text, and the matching result. In our problem, the texts and patterns are not static, and the pre-processing on the text is the encryption, not including building the index and others; any pre-processing on the patterns is allowed. We present pattern matching algorithms for ciphertexts of the fully homomorphic encryption. The time for decrypting the matching results is shorter than that of decrypting-then-matching of the ciphertext. We implement the pattern matching algorithms using HElib library. Several experiments are conducted to test the performance of the algorithm.