To efficiently detect Covid-19 like pandemic infection body area network (BAN) can be used in smart society. Whenever two BUs come close to each other, inter-BAN communication (IBC) takes place. BAN user (BU) stores her Covid status and IBC into the distributed immutable database in blockchain network for tampering free contact tracing. As Covid status and inter-BAN communication (IBC) are privacy sensitive information, BU stores her Covid status and IBC in encrypted form using public key of trusted authority (TA). Public key of TA is used to encrypt IBC event and it is stored in blockchain network. Adjacency matrix data structure has been used to maintain both IBC and Covid status in the blockchain network. Adjacency matrix element \(A_{i,j}, i\ne j\) keeps the IBC status between \(BU_i\) and \(BU_j\) . Diagonal element of adjacency matrix, \(A_{i,i}\) keeps the Covid status of \(BU_i\) . Refreshing of key of TA is required and so is the random numbers generated by BU which are being used in adjacency matrix data structure. Update of TA key and BU generated random numbers is necessary for security reasons. Random number update should not affect the other information present in adjacency matrix elements. Miners use homomorphic encryption for updating the BU generated random numbers. TA generates proxy re-encryption key \(RK_{K\rightarrow K^\prime }\) by which Mi obtains ciphertext \(E_{K^\prime }(m)\) from \(E_K(m)\) to update the adjacency matrix elements without losing relevant Covid status or IBC status. The proposed framework in this work provides the management of privacy-preserved key and random values update in blockchain network. Security analysis of the proposed framework has also been done.