Modern cryptography targeted towards providing data confidentiality still pose some limitations. The security of public-key cryptography is based on unproven assumptions associated with the hardness /complicatedness of certain mathematical problems. However, public-key cryptography is not unconditionally secure: there is no proof that the problems on which it is based are intractable or even that their complexity is not polynomial. Therefore, public-key cryptography is not immune to unexpectedly strong computational power or better cryptanalysis techniques. The strength of modern cryptography is being weakened and with advances of big data, could gradually be suppressed. Moreover, most of the currently used public-key cryptographic schemes could be cracked in polynomial time with a quantum computer. This paper presents a renewed focus in fortifying the confidentiality of big data by proposing a quantum-cryptographic protocol. A framework was constructed for realizing the protocol, considering some characteristics of big data and conceptualized using defined propositions and theorems.