In this section, we address problems of the current version of TCP.
TCP provides fundamental communication service and is used by many application protocols. Therefore, TCP becomes one of the most popular protocol. But TCP has several security problems as follows.
TCP has a checksum field. This field is used in order to identify a modification of a segment. However, since this field is not protected against the message modification attacks, it is possible to modify any TCP segments. Moreover, there is no ways for peer entities to find out the message modification attacks.
TCP transports stream data used in the application layer. Since TCP does not provide any data encryption functions, anyone can gain any valuable information.
TCP certifies a peer entity by a source IP address and a port number. However, it is possible to modify the source address and port number.