Towards distributing block ciphers computations

Providing data confidentiality for energyconstrained devices has proven to be a hard problem. Over the years many efficient implementations of well-known block ciphers, as well as a large number of new “lightweight” block ciphers, have been introduced. We propose to distribute block ciphers encryption and decryption operations between a subset of “trusted” nodes. Any block cipher, lightweight or not, can benefit from it. In particular, we analyze the energy consumption of AES128 in Cipher Block Chaining (CBC) mode and measure the energy savings that a distributed computation of AES128-CBC can give. We show that, by leveraging this distributed computation, a node can save up to 73% and up to 81% of the energy normally spent in encryption and decryption, respectively. This has relevant implications in Internet of Things scenarios.