Techniques for encrypting documents in a search index may include: receiving a document for inclusion in a search index of a search system, where the document has an associated access control list (ACL), and the ACL includes data for use in restricting access to the document to users of the search system having credentials that match corresponding data in the ACL; encrypting the document using a first key to produce an encrypted document; generating a wrapped key for the document by encrypting both the first key and the ACL using a second key; and storing, along with the search index, the encrypted document in association with the wrapped key and an identifier for the document.