Along with the growth of the computer system and networks, the mysterious and malicious threats and attacks on the computer systems are also increasing exponentially. There is a need of continuous evaluation of the security of a network and enhancement of the network attack detection system, which will be able to detect different attacks along with the characteristics of the attacks. In previous work, the port scan attack is considered as precursors to an attack and the target was to provide the mitigation technique for the particular port scan attack. There have been relatively few empirical studies done for port scan related attacks and those that do exist may no longer reflect the impact of such attacks on the functionalities of the UTM/network device and on the network. To address this lack of knowledge, this experiment is carried out in fully controlled test bed environment wherein a set of varieties of attack can be simulated and impact of attack(s) is analyzed and appropriate mitigation technique is suggested to mitigate the port scan attack. The experiment result indicates that the port scan mitigation implementation on UTM helps reducing the load on the UTM device and reduces network congestion effectively.

The communication of digital assets on the internet infrastructure is increasing in its volume with threats on its security with regard to active and passive attacks of eavesdroppers. This concern has opened up the research channel to improve the techniques of secure and reliable communication protecting intellectual property rights and message security. Constant efforts of researchers in this area to achieve communication at faster rate maintaining security of digital assets, is giving improved techniques to achieve the goal. The efforts made here in this work are in the direction to enhance level of security in making faster reliable and secure communication. In spite of continued efforts, still as on today, it is challenging to hide the communication from eavesdropper. The disciplines of Cryptography, Steganography and Digital Watermarking are still popular areas of research. They are continuously digging to find robust and effective algorithms to protect digital communications and digital assets. It is very true that if the complexity in algorithm is increased, higher security level can be achieved. In the reviewed work, Researchers have developed algorithms for text encryption and embedment in digital watermarking using LSB at cost of time. The proposed work is targeted to maintain the tradeoff between the complexity level of algorithm and security level of message considering the time factor. The proposed work has evolved with two algorithms: AMEADT (ASCII Message Encryption and Decryption Technique) to protect secret message and AMEAET (ASCII Message Embedment and Extraction Technique) to embed encrypted text to digital image. The implementation of these algorithms has resulted in justifying higher level of security with comparatively lower level of complexity of algorithm.