Explain how RSA can help in creating digital signatures. How

does a digital signature work in an e-mail system? Can a digital signature in an e-mail avoid packet sniffing?
-What is the basic difference between symmetric and public-key cryptography?
-Research the Walden University Library and explain why public-key cryptography is used more than symmetric-key cryptography. Research the Walden University Library and explain whether symmetric-key cryptography is still used in modern security applications (for example, for sending packets in a network). Additionally, cite three practical applications of public-key cryptography (for example, securing financial transaction) and explain why public-key cryptography is the best cryptographic technique in each case. Please provide references.