  We present the design and implementation of the PeerShare, a system that can
be used by applications to securely distribute sensitive data to social
contacts of a user. PeerShare incorporates a generic framework that allows
different applications to distribute data with different security requirements.
By using interfaces available from existing popular social networks. PeerShare
is designed to be easy to use for both end users as well as developers of
applications. PeerShare can be used to distribute shared keys, public keys and
any other data that need to be distributed with authenticity and
confidentiality guarantees to an authorized set of recipients, specified in
terms of social relationships. We have used \peershare already in three
different applications and plan to make it available for developers.

Cryptography and Security