Techniques for efficiently searching encrypted searchable spaces. For
example, embodiments of the present invention provide techniques for
searching a plurality of files that are stored in encrypted (or
ciphertext) form. According to embodiments of the present invention, the
search can usually be performed by decrypting only a portion of the
encrypted searchable space. According to an embodiment of the present
invention, the search techniques determine a set of files comprising one
or more files from the plurality of encrypted files that contain a
user-specified query element. The set of files is usually determined by
decrypting only a subset of the plurality of encrypted files.