Privacy is an important concept in the field of data communications. Faxed business letters, electronic mails and cloud computing can be intercepted through tapped phone lines or intercepted transmissions mediums without the information of the sender or receiver. Cloud computing is known as the new generation architecture of IT enterprise. The cloud computing concept offers dynamically useable resources provisioned as a service over the Internet. However, there are still some challenges to be solved. Most important the issues are based on the concept of security and trust.