Chain-based big data access control infrastructure

Abstract

Technological advancements have brought about the rise of data and other digital assets in our world today. The major problems with data today are its security and management, more importantly access control. These factors when not tackled effectively can lead to many compromises. The blockchain is an effective technology that ensures utmost security, trust, and maximum access control in big data systems. However, almost all the transactions on a blockchain network are stored in the platform. This process reduces the data storage, as the storage of all transactions sometimes creates unnecessary overheads. In this paper, an off-chain-based sovereign blockchain is proposed, where a virtual container is created for parties to transact in. At the end of a transaction, and satisfying each party, the container is destroyed but the results are stored on the sovereign blockchain network. This effectively decreases the amount of data that would have been stored on the network. The effectiveness of our system is compared with other schemes, and we could infer that our proposed system outperforms the already-existing ones.

Appendix: Two-factor authentication scheme

In this paper, an ECDSA authentication scheme, which was proposed by Christopher Mann and Daniel Loebenberger [28], is adopted. The scheme has three phases: initialization, construction of an ephemeral key, and a signature formulation.

• Initialization An ECDSA key pair (d, Q) is generated. The private key is multiplicatively shared between the user and the system, by selecting $d_U \in {\mathbb {Z}_n}^*$ pseudorandomly and computing $d_S = d \times {d_U}^{-1}$ in ${\mathbb {Z}_n}^*$. Then, $d=d_Ud_S$ and the user gets its share of the key $d_U$, while the system also takes $d_S$. Both user and system then compute their corresponding public keys $Q_U=d_UG$ and $Q_S=d_SG$, where G is a finite base point on an elliptic curve, E. Two key pairs, $(sk_U,pk_U)$ and $(sk_S,pk_S)$, for a homomorphic public key encryption scheme are generated and distributed to the user and system accordingly.

• Key construction In this phase, a shared ephemeral secret $k=k_Uk_S \in {\mathbb {Z}_n}^*$ is generated together with the corresponding public key $V=kG \in E$. The user and the system also compute the public keys corresponding to their shares of this secret as $V_U=k_UG$ and $V_S=k_SG \in E$. Also, the user commits to the two values ${k_U}^{-1}$ and ${k_U}^{-1}d_U$ in ${\mathbb {Z}_n}^*$ by sending the corresponding encryptions under $pk_U$ to the system.

• Signature formulation In the final phase, the system uses the two commitments together with the homomorphic property of the encryption scheme to finally compute the second part of the ECDSA signature.