Generally Unauthorized and hidden used to send information that violates Information security policy.
*Covert Storage Channels* - They are a line of communication that can be seen by everyone but not understand by everyone. Processes are able to communicate through some type of storage on the system.
* Stagnograhy is a type of Covert Storage Channel. Example - Hiding a picture or a message inside a PDF Document.
*Covert Timing Channel* - One precess relays information to another by modulating the use of system resources. For example, mixing illegitimate traffic with legitimated traffic.
* Cache Timing Attacks
* Cache memory sits in between processor and memory. It is used for faster processing.