Blockchain privacy‐preserving smart contract centric multiplemultipartykey agreement over largeWANETs

Abstract

With the rapid increase in the popularity of groupware applications whose security mainly relied on the key being used, which made multi‐party/group secret key agreements significant. However, the brute‐force attacks to interpret the group key made group communication vulnerable. The logical solution to overcome this is changing the group key frequently. In this direction, we propose blockchain‐based multiple shared keys agreement among a group of participants. As with conventional methods, the proposed protocol does not rely on strong random number generation and/or master key. In this technique, the privacy‐preserving smart contract acts as group controller (GC) and forms two parties with each of the other nodes. The GC, while generating these two‐party keys in the first round instead of exchanging one public key, it exchanges “m” public keys with each of the other nodes and generates m2 shared two‐party keys with each of the respective nodes. Now in the second round, GC generates m2 sequential products of two‐party shared keys and stores them securely as private data objects in the privacy‐preserving smart contract. Next GC computes m2sequential public keys to each of the respective nodes by multiplying these products with the inverse of individual members shared keys sequentially of the group nodes in trusted execution environment and shares them with respective group nodes. On receiving respective public keys, each group node computes the multiple multiparty shared keys by multiplying it with their individual shared keys. Furthermore, an upper limit for the number of shared keys obtained in terms of the number of keys exchanged.

Questioning the Security of Three Recent Authentication and Key Agreement Protocols

“…[38], [39], or chaotic map such as [40]. Some other researchers tried to provide decentralized solutions by basing their protocol on the blockchain-based platforms such as [41], [42], [43]. Some recent works also have been conducted also that could be good choices for post quantum cryptography, because they are based on primitives that are secure against quantum computer such as lattice based cryptography, e.g.…”

Practical KGC-Free Polynomial-Based Multiple Group Keys Agreement for IoT Health Care Systems

“…Like the above scheme, in [34], this scheme also uses asymmetric encryption to establish multigroup keys. Recently, the authors of [37] proposed a multiparty key agreement based on elliptic curve cryptography (ECC) encryption, which is more computational efficient than RSA, but this protocol also needs a group controller (GC) and rekeying overhead. Hsu et al [38] proposed an efficient useroriented multigroup key agreement scheme based on secret sharing, which relies on the trusted key generation center (KGC) to negotiate keys.…”

“…By comparing with the recently proposed multigroup key agreement scheme [34,37] based on public key encryption, the performance of our scheme is evaluated in this section.…”

“…Compared with the public-key-based multigroup key establishment schemes [34,37], our protocol has the following advantages:…”

“…To overcome this drawback, in our protocol, KGC-free multigroup keys generation is performed by all group members. (b) In the public key broadcast-based scheme [34,37],…”