SummaryImprovement of privacy and security in data centers is challenging with proficient safety key managing. So as to resolve this issue, data centers require proficient quantum cryptographic techniques with authentication methods that are suitable to improve the privacy and security with lesser intricacy. In addition, quantum cryptography (QC) offers maximal security with lesser complication, which raises the security strength and storing capability of big data. This work intends to introduce a QC oriented data security model in cloud via electing the optimal private key. Here, attribute based encryption (ABE) is performed for ensuring better data transmission among the nodes in cloud. For key generation in ABE, improved QKD is adopted in this work. Depending upon this, the decryption and encryption is done. Moreover, for optimal secret key selection in ABE, self‐modified Aquila optimization (SM‐AO) scheme is deployed. Further, analysis is done depending upon varied metrics.