##sse-rb

This gem implements symmetric searchable encryption, as described in Song et al, 2000. This scheme provides a secure, simple and fast algorithm for searching over encrypted data. It achieves searchable encryption by crafting, for each word, a special two-layered encryption construct. Given a trapdoor, the server can strip the outer layer and assert whether the inner layer matches a search query. The algorithm performs searches in O(n) time.

###Usage

require 'sse'

key = OpenSSL::Digest::SHA256.digest('')
cipher = SSE::Cipher.new(key)

ciphs = cipher.encrypt_words(key, ["captain", "doctor", "captain"])
words = cipher.decrypt_words(key, ciphs)

puts words == ["captain", "doctor", "captain"] # => true
                                                 
token = cipher.generate_token(key, "captain")    
puts cipher.search_exists(token, ciphs)        # => true
                                                 
puts cipher.search_words(token, ciphs)         # => [0,2]

token = cipher.generate_token(key, "driver")
puts cipher.search_exists(token, ciphs)        # => false

###Credits

A Javascript implementation provided insight into several implementation details. CryptDB provided a reference implementation for the Song et al. paper.

###License

This software is released under the GNU Affero General Public License. If this license does not suit your needs, please contact me.