Briefly and clearly summarize (1-3 sentences) how public/private key cryptography can guarantee each of the following. Make sure to include the phrases public key and private key in each answer and specify who has which key. Do not worry about how we trust keys, just focus on use of public/private keys. A: I can download a program from Microsoft and make sure it actually came from them. B: I can send a message to Bank of America and be sure only they can read it.