Protected search index

Abstract

A messaging service provides a search mechanism that utilizes a protected index. The protected index is generated by converting documents maintained by the messaging service into a set of tokens or words. Each token is converted to a corresponding value using a transformation such as a cryptographic hash function. The values are placed into an index that allows the messaging service to efficiently identify a set of documents associated with each particular value. When a document search request is submitted to the messaging service, the messaging service uses the transformation to generate corresponding values for each term in the search request, and uses the index to identify sets of documents associated with the values corresponding to the search terms. The messaging service applies search logic associated with the search request to the identified sets of documents to produce a final set of documents satisfying search request.