Encryption Lab Paper 3 page

3-page lab report
One page description of GPG what does it do and how, and the components of GPG4win.
Answer the following questions:
How do I know that the file I downloaded has not been tampered with?
Compare and contrast Private Key (symmetric) and Public Key (asymmetric) encryption. 
Why do we need PKI for secure email?
In what ways can we share our public keys with others?