10. A method for partial encryption of a document, the method comprising: Paginating, by at least one processor, the document into at least one sub-page according to characteristics of a specific device class; and separately encrypting, by the at least one processor, a to-be-encrypted element of the at least one sub-page using a partial encryption mechanism known by a client device and based on the characteristics of the specific device class, wherein when the to-be-encrypted element of the at least one sub-page comprises the entire sub-page, an encryptor encrypts the entire sub-page, and when the to-be-encrypted element of the at least one sub-page comprises less than all elements of the entire sub-page, the encryptor encrypts only the to-be-encrypted element, and further wherein the to-be-encrypted element of the at least one sub-page is surrounded with a corresponding encryption tag.
10. A method for partial encryption of a document, the method comprising: Paginating, by at least one processor, the document into at least one sub-page according to characteristics of a specific device class; and separately encrypting, by the at least one processor, a to-be-encrypted element of the at least one sub-page using a partial encryption mechanism known by a client device and based on the characteristics of the specific device class, wherein when the to-be-encrypted element of the at least one sub-page comprises the entire sub-page, an encryptor encrypts the entire sub-page, and when the to-be-encrypted element of the at least one sub-page comprises less than all elements of the entire sub-page, the encryptor encrypts only the to-be-encrypted element, and further wherein the to-be-encrypted element of the at least one sub-page is surrounded with a corresponding encryption tag. 13. The method of claim 10 , further comprising: identifying the to-be-encrypted element of the at least one sub-page by a corresponding encryption tag surrounding the to-be-encrypted element.