Today's the last day of ACNS 2012. As we'll be immediately heading off to the conference VIP dinner after the last session and I'll probably don't want to whip out my laptop afterwards ;-) I'll give a short day's summary before the last session (dedicated to web security) takes place.
Today was dedicated mainly to security and privacy issues in current and emerging application fields like social networks, cloud systems and smart grids. Personally I found the talks regarding smart grids interesting as this field is very important to help us to reduce overall power consumption (through an increase of awareness in consumers) as well as to increase the efficiency of energy use (through the interplay of a smart grid with smart household appliances and devices). While it is clear that there is a communication need for individual smart meters to the grid operator and/or electricity provider, the different solutions presented in this session vary in the requirement of communication amongst smart meters themselves. The first system presented by Hsiao-Ying Lin does not require such communication but in turn has a few shortcomings which the authors hope to address in their future work. The second system presented by Zekeriya Erking requires communication amongst smart meters and employs an additive homomorphic encryption (Paillier) in a modified variant so that individual power readings cannot be decrypted, but a sum of such readings can. While this is certainly an interesting approach, it also requires all smart meters to be "honest" (as a single "dishonest" smart meter contributing malformated ciphertexts will prevent correct decryption of the sum of the readings).