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Constant Length Padding

Classification Key : Exterior Security, Information Disclosure


An anonymity preserving node has to receive packets from many different nodes to create the anonymity set. If the node implements representation morphing or layered encryption, then after the encoding change the size of the packet changes. This change can be traced back to the original packet and by backtracking an attacker can compromise sender anonymity. How can this be avoided?


Make all the data packets to be of same length. After the encoding, add dummy padding at the end of the packet to make the packet of same size of the input data packet.

Known Uses

Constant length padding in Morphmix.

Related Patterns

Representation Morphing, Layered Encryption


Hafiz Privacy Patterns


Anonymity, Privacy, Packet


Last modified: May 05, 2012

Conceived and Maintained by: Munawar Hafiz