Hash Constructions for CoAP under an IoT Environment

Hash construction is a very famous method. This is popular because the hash function is found in almost all security algorithms. Various uses of hash functions have been found since the early stages of computing and communication. The most fascinating thing of a hash construction is its one way property. One way property of a hash function has been used in many places for example, generating security key for two party communications and creating a digital signature to safeguard an important document. The hash functions are in use from very long, i.e. when the Uninterrupted Power Supply (UPS) based machines were communicated. Even at that time also the hash functions were of three types, i.e. MD, SHA and BLAKE. When it comes to lightweight computing, i.e. communicating machines without direct power supply or with stored energy only, the hash function is considered to be the best. A new design of hashing based on a sponge construction is proposed for the secure communication between constrained devices in lightweight fashion. There were many other developments in this field occurred before the sponge construction comes into existence those are JH, Keccak, BLAKE and SHA. Although there are a huge number of hash constructions are available, the original need of a lightweight IoT environment is still not fulfilled. In this presented paper, the authors will discuss all working methodology for hash constructions along with their positive and negative aspects. Also, a fair comparison of several hash design has be given for the easiness of its users.