Back to Security Pattern Catalog




Morphed Representation


Classification Key : Exterior Security, Information Disclosure

Problem

The incoming data packets in a mix network carry the data content. They also have meta-characteristics associated like the time of packet generation, ingress order of packets etc. The mix network obfuscates these meta-characteristics by adding random delays to the ingress packets, or by batching a number of ingress packets before releasing the packets. However, if the mix concepts do not obfuscate the data content, the incoming and outgoing data packets have the same representation and they can be correlated trivially. This compromises sender anonymity and sender and receiver unlinkability. How can the representation of the data be obfuscated?

Solution

Change the representation of the incoming data packet such that the outgoing packets look different from incoming packets. The incoming packets are encrypted using a key shared between the sending node and the mix node. At the mix node, decrypt the packet and then re-encrypt it with the key shared between the mix node and the subsequent node.

Known Uses

Changing encoding of data fields in a mix network.

Related Patterns

Anonymity Set, Layered Encryption

Source

Hafiz Privacy Patterns

Tags

Anonymity, Privacy


 

Last modified: May 05, 2012

Conceived and Maintained by: Munawar Hafiz