A brief overview of modern cryptographic tools with application to Internet

Here a brief overview of some of the cryptographic tools used in Internet today is illustrated. This document briefly introduces cryptography starting from a short resume of historical events showing the evolution and role played by cryptography narrating some representative real life events in history. A more formal introduction mentioning the advantages obtainable with cryptography is then undertaken starting from symmetric and asymmetric cryptography. Other uses of cryptography are then explained to finally present two widely used communication protocols in Internet. Representative examples are provided reverting to a minimal mathematical approach

Barrel Shifter Physical Unclonable Function Based Encryption

Physical Unclonable Functions (PUFs) are circuits designed to extract physical randomness from the underlying circuit. This randomness depends on the manufacturing process. It differs for each device enabling chip-level authentication and key generation applications. We present a protocol utilizing a PUF for secure data transmission. Parties each have a PUF used for encryption and decryption; this is facilitated by constraining the PUF to be commutative. This framework is evaluated with a primitive permutation network - a barrel shifter. Physical randomness is derived from the delay of different shift paths. Barrel shifter (BS) PUF captures the delay of different shift paths. This delay is entangled with message bits before they are sent across an insecure channel. BS-PUF is implemented using transmission gates; their characteristics ensure same-chip reproducibility, a necessary property of PUFs. Post-layout simulations of a common centroid layout 8-level barrel shifter in 0.13 {\mu}m technology assess uniqueness, stability and randomness properties. BS-PUFs pass all selected NIST statistical randomness tests. Stability similar to Ring Oscillator (RO) PUFs under environment variation is shown. Logistic regression of 100,000 plaintext-ciphertext pairs (PCPs) failed to successfully model BS- PUF behavior

SMCP: a Secure Mobile Crowdsensing Protocol for fog-based applications

The possibility of performing complex data analysis through sets of cooperating personal smart devices has recently encouraged the definition of new distributed computing paradigms. The general idea behind these approaches is to move early analysis towards the edge of the network, while relying on other intermediate (fog) or remote (cloud) devices for computations of increasing complexity. Unfortunately, because both of their distributed nature and high degree of modularity, edge-fog-cloud computing systems are particularly prone to cyber security attacks that can be performed against every element of the infrastructure. In order to address this issue, in this paper we present SMCP, a Secure Mobile Crowdsensing Protocol for fog-based applications that exploit lightweight encryption techniques that are particularly suited for low-power mobile edge devices. In order to assess the performance of the proposed security mechanisms, we consider as case study a distributed human activity recognition scenario in which machine learning algorithms are performed by users’ personal smart devices at the edge and fog layers. The functionalities provided by SMCP have been directly compared with two state-of-the-art security protocols. Results show that our approach allows to achieve a higher degree of security while maintaining a low computational cost

Practical implementation and performance analysis on security of sensor networks

A wireless sensor network (WSN) is a network made of thousands of sensing elements called as nodes with wireless capabilities. Their application is varied and diverse ranging from military to domestic and household. As the world of self-organizing sensor networks tip to the edge of maximum utilization, their wider deployment is adding pressure on the security front. Powerful laptops and workstations make it more challenging for small sensors. In addition, there are many security challenges in WSN, e.g- confidentiality, authentication, freshness, integrity etc. Contributions of this work are as follows: “Symmetric” security implementation: This thesis work designs a symmetric-key based security in sensor hardware in the Link layer of sensor network protocols. Link Layer security can protect a wireless network by denying access to the network itself before a user is successfully authenticated. This prevents attacks against the network infrastructure and protects the network from devastating attacks. “Public key” implementation in sensor hardware: Asymmetric key techniques are attractive for authentication data or session keys. Traditional schemes like RSA require considerable amounts of resources which in the past has limited their use. This thesis has implemented Elliptic Curve Cryptography (ECC) in Mica2 hardware, which is an approach to public-key cryptography based on the mathematics of elliptic curves. Quantitative overhead analysis: This thesis work analyzes the wireless communication overhead (No. of packets transmitted) vs the (transmit and receive) energy consumed in mJoules and memory storage overhead (bytes) for ECC as compared to the symmetric counterpart for the implemented WSN security protocols

Design and Implementation of a Secure Wireless Mote-Based Medical Sensor Network

A medical sensor network can wirelessly monitor vital signs of humans, making it useful for long-term health care without sacrificing patient comfort and mobility. For such a network to be viable, its design must protect data privacy and authenticity given that medical data are highly sensitive. We identify the unique security challenges of such a sensor network and propose a set of resource-efficient mechanisms to address these challenges. Our solution includes (1) a novel two-tier scheme for verifying the authenticity of patient data, (2) a secure key agreement protocol to set up shared keys between sensor nodes and base stations, and (3) symmetric encryption/decryption for protecting data confidentiality and integrity. We have implemented the proposed mechanisms on a wireless mote platform, and our results confirm their feasibility