MIME (Multipurpose Internet Mail Extension) | Computer Networks - Computer Science Engineering (CSE) PDF Download

MIME(Multipurpose Internet Mail Extention)
This allows the transmission of Non ASCII data through the email, MIME allows arbitrary data to be encoded in ASCII and sent in a standard email message. Each MIME message includes information that tells the recipient the type of data and the type of encoding used and this information along with the MIME version resides in the MIME header. Typical MIME header looks like,

MIME-Version: 1.0

Content-Description:

Content-Id:

Content-Type: image/gif

Content-Transfer-Encoding: base64

Content Description: contains the file name of the file that is being sent. Content -Type : is an important field that specifies the data format ie. tells what kind of data is being sent. It contains two identifiers a content type and a subtype separated by a slash. for e.g. image/gif There are 7 Content Types -
1.     text
2.     image
3.     video
4.     audio
5.     application

The delivery protocols determine how the mail is transferred by the mail transfer agent to the user agent which provides an interface for reading mails.

Ensuring Network Security

1. How to ensure that nobody else reads your mail?
2. How to be sure that the mail has not been seen by someone else in your name?
3. Integrity ie. mail has not been tampered with
4. Non-Repudiability- means once I send a mail I cannot deny it, and this fact can be proved to a third person
5. Authentication