In PKI data encrypted using a public key can only be decrypted by the public key's private pair. James needs to send the email so only Bob can decrypt it, so he will use Bob's public key. When Bob gets the email he will use his private key to decrypt it, therefor ensuring confidentiality.
Email encryption is encryption of email messages to protect the content from being read by other entities than the intended recipients. Email encryption may also include authentication.
Email is prone to disclosure of information. Most emails are currently transmitted in the clear (not encrypted) form. By means of some available tools, persons other than the designated recipients can read the email contents.Email encryption can rely on public-key cryptography, in which users can each publish a public …