Jeffrey Encryption is completly done locally on your browser. THis means that your data never leaves your computer, and nobody can see it but you(and the people you send the data to).
Jeffrey Encryption is powered by the
Stanford Javascript Crypto Library, which uses Industry standard AES encryption, SHA256 hashing, and fresh random salts. For more information, see the
SJCL Library at
http://bitwiseshiftleft.github.io/sjcl/.