Ciphertext-Policy Attribute-Based Encryption Scheme for Secure Organizations’ Bitcoin Wallet Access

Abstract

Bitcoin is a totally decentralized digital cryptocurrency stored in a wallet managed by the user using his private key. In organizations, to allow the employees to access organization wallet, bitcoins need to be managed based on each department’s or team’s budget. Organization’s hierarchy need each department to have its bitcoins independently and control the wallet by employee’s attributes as his position, email, and department to make the access more realistic and flexible. In this paper, the organization’s wallet (superwallet) is divided into subwallets; a subwallet is assigned for each department based on this department’s budget. This paper introduces a ciphertext-policy attributed-based encryption (CP-ABE) to control the access of organization’s bitcoin subwallets. In the proposed CP-ABE scheme, a tree-based access structure will be used including AND, OR, and threshold gates with a flexible and secure access structure model. Therefore, the proposed scheme can keep the structures of organizations. Moreover, security of the proposed scheme has been analyzed.