Unencrypted, unauthenticated metadata <i>allow</i> tampering with your data: <a href="http:&#x2F;&#x2F;www.6nelweb.com&#x2F;bio&#x2F;papers&#x2F;pwvault-ESORICS12-ext.pdf" rel="nofollow">http:&#x2F;&#x2F;www.6nelweb.com&#x2F;bio&#x2F;papers&#x2F;pwvault-ESORICS12-ext.pdf</a>