EnCE EnCase Computer Forensics: The Official EnCase Certified Examiner Study Guide, 3rd Edition

Base64 Encoding

While I’m on the topic of email, it is a good time to discuss email attachments. If you’ll recall from the discussion of the ASCII table, all of the printable characters are contained within the first 128 bytes of the 256-byte table. These first 128 bytes are also called low-bit ASCII because all 128 characters can be represented using 7 bits.

When the first protocols were developed for communicating between computers, the characters transmitted were low-bit ASCII (7 bits), and the 8th bit of each byte was used for parity or error checking to make sure the 7 bits arrived accurately. All was well for a while until programs or other files containing binary data needed to be sent. Such a data transfer involved sending characters ...