Decades went by since Mark Weiser published his influential work on how a computer of the 21st century would look like. Over the years, some of the UbiComp features presented in that paper have been gradually adopted by industry players in the technology market. While this technological evolution resulted in many benefits to our society, it has also posed, along the way, countless challenges that we have yet to surpass. In this paper, we address major challenges from two areas that most afflict the UbiComp revolution: security and privacy. We examine open problems on software protection, long-term security, cryptography engineering, and privacy implications. We also point out promising directions towards the solutions of those problems. We claim that if we get all this right, we will turn the science fiction of UbiComp into science fact.

Information-centric Networks (ICN) aims to improve content delivery by promoting the content as the protagonist of the network layer. By naming, routing, and forwarding named content directly on the network layer, ICN allows the same content to satisfy requests from different users, enabling innetwork caches to place contents strategically near the interested users. This characteristic is especially interesting for multimedia content distribution, since it represents a better quality of experience for users due to low round-trip time, bandwidth use, and load on content providers. However, caching protected multimedia content on uncontrolled third party devices may impair access control policies enforcement by the content providers. Many encryption-based access control solutions have been proposed for ICN, applying different cryptographic strategies leading to distinct features which may not be appropriate for multimedia content protection. In this paper, we simulate, evaluate, and discuss the individual characteristics of three encryption-based access control solutions in light of multimedia distribution in ICN. We show that leveraging cache efficiency, computational load to encrypt and decrypt content, and user revocation are the biggest challenges for the enforcement of access control policies on ICN.

In this paper, we describe a family of symmetric cryptographic algorithms and present its cryptanalysis. Specifically, we use differential fault analysis to show a fault attack threat to the block cipher family named Simon. In addition, we present the improvement of a fault attack based on a differential attack method. Moreover, we are the first to to extract the entire secret key using only one round. This property is important because an attacker has to control the hardware to inject faults. However, if the attacker has control of only few hardware components and they compute only one round, previous attacks are not able to recover the entire key. With this side-channel analysis, an attacker can inject faults in one round of Simon with block of 96 or 128 bits to recover therespective entire key of 96 or 128 bits without using SAT solver neither computing Grobner bases. The key can be recoveredusing only differential fault analysis.

The Information-centric Network (ICN) paradigm is an important initiative toward an Internet architecture more suitable for content distribution. The change it imposes by naming, routing, and forwarding content directly on the network layer empowers the architecture with several interesting characteristics, such as in-network caching. As contents are meaningful for different users, they can be opportunistically cached and easily accessed by them, which improves content delivery and user experience. However, the fact that users can retrieve content through caches without interacting with the content provider raises security concerns regarding unauthorized access and the enforcement of access control policies. In this context, we propose an access control solution for ICN by adapting and optimizing a proxy re-encryption scheme, reducing up to 33% the processing time. The proposed solution is perfectly aligned with ICN demands, simultaneously ensuring content protection against unauthorized access of contents retrieved from unrestricted in-network caches as well as access control policies enforcement for legitimate users.

Abstract Studies on smart grid and quantum mechanics have potential to yield several benefits to society, with the former resulting in economic and environmental benefits and the latter providing perfect security and privacy at affordable costs. Recently, security and privacy have become important issues in electrical power grids. In this paper, we describe two quantum privacy‐enhancing protocols: one of them requires that the parties initially share a certain amount of quantum entangled states, while the other uses only quantum key distribution methods without sharing quantum entangled states. The two proposed protocols are resistant to attacks from quantum computers. This paper also describes some recent advances of classical and quantum privacy‐enhancing technologies. Copyright © 2014 John Wiley & Sons, Ltd.

We present an innovative protocol combining innetwork data aggregation and smart meter billing for a smart grid scenario. The former enables an energy supplier to allocate and balance resources. The latter provides dynamic pricing schemes according to fine-grained consumption profiles. Moreover, smart meters and their energy supplier can prove their billing values. Since the energy supplier knows the amount of generated electricity and the consolidated consumption in a round of measurements, the energy supplier can detect energy loss and fraud. To preserve customers' privacy, we use a homomorphic commitment scheme with a homomorphic encryption scheme. All data sent from a meter to any other component in the communication network is either a commitment or an encrypted message. To provide security and privacy, we only require software modifications, leaving the hardware of the smart grid unchanged.

Digital societies increasingly rely on secure communication between parties. Certificate enrollment protocols are used by certificate authorities to issue public key certificates to clients. Key agreement protocols, such as Diffie-Hellman, are used to compute secret keys, using public keys as input, for establishing secure communication channels. Whenever the keys are generated by clients, the bootstrap process requires either (a) an out-of-band verification for certification of keys when those are generated by the clients themselves, or (b) a trusted server to generate both the public and secret parameters. This paper presents a novel constrained key agreement protocol, built upon a constrained Diffie-Hellman, which is used to generate a secure public-private key pair, and to set up a certification environment without disclosing the private keys. In this way, the servers can guarantee that the generated key parameters are safe, and the clients do not disclose any secret information to the servers.