US Patent 10127391 Encrypted search indexes

In one example, a method for searching data includes creating a set of tokens corresponding to data of an encrypted dataset, and then encrypting the tokens. Next, an encrypted search index is created that includes the encrypted tokens and that excludes any positional information concerning the data to which the encrypted tokens correspond. A query is then defined that includes one or more encrypted search tokens. Next, search results are received that identify any matches between the encrypted search tokens and the encrypted tokens of the encrypted search index. Finally, the data that corresponds to any identified tokens that match a token of the encrypted search index is decrypted.