Dogs in warfare have a long history starting in ancient times. From war dogs trained in combat to their use as scouts, sentries and trackers, their uses have been varied and some continue to exist in modern military usage.
Encryption is the coding or scrambling of information so that it can only be decoded and read by someone who has the correct decoding key. Encryption is used in secure Web sites as well as other mediums of data transfer. If a third party were to intercept the information you sent via an encrypted connection, they would not be able to read it.
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). By means of some available tools, persons other than the designated recipients can read the email contents. Email encryption has been used by journalists and regular users to protect privacy.