WILDCARD SEARCH IN ENCRYPTED TEXT USING ORDER PRESERVING ENCRYPTION

摘要

A encrypted text wildcard search method enables wildcard search of encrypted text by using a permuterm index storing permuted keyword strings that are encrypted using an order preserving encryption algorithm. The permuted keyword strings are encrypted using an order preserving encryption algorithm or a modular order preserving encryption algorithm and stored in the permuterm index. In response to a search query containing a wildcard search term, the encrypted text wildcard search method transforms the wildcard search term to a permuted search term having a prefix search format. The permuted search term having the prefix search format is then used to perform a range query of the permuterm index to retrieve permuted keyword strings having ciphertext values that fall within the range query. In some embodiments, the encrypted text wildcard search method enables prefix search, suffix search, inner-wildcard search, substring search and multiple wildcard search of encrypted text.

主权项

1. A method for performing wildcard search of encrypted cloud stored data comprising:
receiving, at a network intermediary, a document destined for a cloud service provider; encrypting, at a network intermediary, the document using a document encryption algorithm; generating a set of permuted keyword strings for each of some or all of the keywords in the document, the set of permuted keyword strings for each keyword being generated by adding a first character delimiter before the first character of the keyword and applying cyclic rotation of the characters of the keyword, including the first character limiter; encrypting the permuted keyword strings using an order preserving encryption algorithm; storing the encrypted permuted keyword strings in a database; and transmitting the encrypted document to the cloud service provider.