People like Jeff are better regarded as hyper-intelligent aliens with a tangential interest in human affairs.

We show that an ad­versa­ry can de­crypt a ci­pher­text by per­for­ming only 14 re­quests per plain­text byte on aver­a­ge. This poses a se­rious and truly prac­tical se­cu­ri­ty thre­at on all cur­rent­ly used im­ple­men­ta­ti­ons of XML En­cryp­ti­on. In a sense the at­tack can be seen as a ge­ne­ra­liza­t­i­on of pad­ding ora­cle at­tacks (Vau­den­ay, Eu­ro­crypt 2002). It ex­ploits a subt­le cor­re­la­ti­on bet­ween the block ci­pher mode of ope­ra­ti­on, the cha­rac­ter en­co­ding of en­cryp­ted text, and the re­s­pon­se be­ha­viour of a Web Ser­vice if an XML mes­sa­ge can­not be par­sed cor­rect­ly.

AES-128, RSA-2048, etc. are widely accepted standards.

Obviously infeasible to break by best attacks in literature.

Implementations are available in public cryptographic libraries such as OpenSSL.

Common security practice is to use those implementations. But cryptography is still
a disaster! Complete failures of confidentiality and integrity

We have designed+implemented a new cryptographic library, NaCl (“salt”), to address
the underlying problems. http://nacl.cace-project.eu, http://nacl.cr.yp.to: source
and extensive documentation.

In this paper, we show how to exploit real-time communication applications to determine the IP address of a targeted user. We focus our study on Skype, although other realtime communication applications may have similar privacy issues. We first design a scheme that calls an identified targeted user inconspicuously to find his IP address, which can be done even if he is behind a NAT. By calling the user periodically, we can then observe the mobility of the user. We show how to scale the scheme to observe the mobility patterns of tens of thousands of users. We also consider the linkability threat, in which the identified user is linked to his Internet usage. We illustrate this threat by combining Skype and BitTorrent to show that it is possible to determine the filesharing usage of identified users. We devise a scheme based on the identification field of the IP datagrams to verify with high accuracy whether the identified user is participating in specific torrents. We conclude that any Internet user can leverage Skype, and potentially other real-time communication systems, to observe the mobility and filesharing usage of tens of millions of identified users.