Mobile cloud computing uses cloud infrastructure to provide apps and services to mobile devices. In this scenario, cloud computing promotes data sharing among authorised users by providing access to resources stored on Cloud Servers (CS). Data sharing is the process of distributing data to various users or applications; however, providing secure access and data protection remains a major concern. To solve this, a novel technique known as Random Self-Generative Schnorr Certificateless Signcryption based Secured Data Sharing (RSGSCS-SDS) is presented to improve data confidentiality in mobile cloud environments. The RSGSCS-SDS approach begins with mobile. In order to access different services, cloud users must register their data with CS. Upon registration, CS uses the Random Self-Generative Schnorr Certificateless Signcryption method to create a unique user's own set of public and private keys. Employing using particular policy attributes, when a user asks for access to data, the server verifies their authorisation. While the user is validated, the server returns the requested data in ciphertext with a corresponding digital signature. The user then checks the signature before decrypting and accessing the contents. The user cannot access the original data until the validity of the signature has been established, ensuring secure access. Outcome of RSGSCS-SDS approach providing protected data distribution. Proposed approach shows better performance of secure data sharing based on metrics of data confidentiality, data integrity, computing time, storage overhead and delay. It shows less delay and storage overhead in addition to improving data confidentiality and data integrity compared to the existing certificateless signcryption method.