Following a meeting with the Chief Technical Officer at CyberMedica, you are requested to provide your opinion in the report on the following cryptographic implementations within the company:

a$)$ With a total of $950$ employees spread across various departments, the company is considering using symmetric encryption for bi$-$directional communication. Is this approach feasible, or are there better alternatives? Provide a detailed answer that includes all calculations related to storage requirements and key distribution complexity.

b$)$ For secure authentication between two servers, the company has implemented the RSA protocol. However, their intranet has been compromised by malware, resulting in the loss of one of the public keys. They managed to retrieve the private key from tamper$-$resistant hardware, with the values d$=29$ and n$=91.$ They are contemplating wiping the server memory and destroying the server, which costs around $$25,000.$ The CTO seeks your advice on whether this is a prudent decision, given that they no longer have the public key for reuse and cannot encrypt the messages $"12,""32,"$ and $"8,"$ which are the one$-$time passwords needed for further authentication server use.

$($please make it correct both parts$)$