Quantum steganography that utilizes the quantum mechanical effect to achieve the purpose of information hiding is a popular topic of quantum information. Recently, E1 Allati et al. proposed a new quantum steganography using the GHZ4 state. Since all of the 8 groups of unitary transformations used in the secret message encoding rule change the GHZ4 state into 6 instead of 8 different quantum states when the global phase is not considered, we point out that a 2-bit instead of a 3-bit secret message can be encoded by one group of the given unitary transformations. To encode a 3-bit secret message by performing a group of unitary transformations on the GHZ4 state, we give another 8 groups of unitary transformations that can change the GHZ4 state into 8 different quantum states. Due to the symmetry of the GHZ4 state, all the possible 16 groups of unitary transformations change the GHZ4 state into 8 different quantum states, so the improved protocol achieves a high efficiency.
In this paper,we first propose a hidden rule among the secure message,the initial tensor product of two Bell states and the final tensor product when respectively applying local unitary transformations to the first particle of the two initial Bell states,and then present a high-efficiency quantum steganography protocol under the control of the hidden rule.In the proposed quantum steganography scheme,a hidden channel is established to transfer a secret message within any quantum secure direct communication(QSDC) scheme that is based on 2-level quantum states and unitary transformations.The secret message hiding/unhiding process is linked with the QSDC process only by unitary transformations.To accurately describe the capacity of a steganography scheme,a quantitative measure,named embedding efficiency,is introduced in this paper.The performance analysis shows that the proposed steganography scheme achieves a high efficiency as well as a good imperceptibility.Moreover,it is shown that this scheme can resist all serious attacks including the intercept-resend attack,measurement-resend attack,auxiliary particle attack and even the Denial of Service attack.To improve the efficiency of the proposed scheme,the hidden rule is extended based on the tensor product of multiple Bell states.
Memory analysis gains a weight in the area of computer live forensics.How to get network connection information is one of the challenges in memory analysis and plays an important role in identifying sources of malicious cyber attack. It is more difficult to fred the drivers and get network connections information from a 64-bit windows 7 memory image file than from a 32-bit operating system memory image f＇de. In this paper, an approach to fred drivers and get network connection information from 64-bit windows 7 memory images is given. The method is verified on 64-bit windows 7 version 6.1.7600 and proved reliable and efficient.
A method to extract information of network connection status information from physical memory on Windows Vista operating system is proposed. Using this method, a forensic examiner can extract accurately the information of current TCP/ IP network connection information, including IDs of processes which established connections, establishing time, local address, local port, remote address, remote port, etc., from a physical memory on Windows Xflsta operating system. This method is reliable and efficient. It is verified on Windows Vista, Windows Vista SP1, Windows Vista SP2.
Although FireWire-based memory acquisition method has been introduced for several years, the methodologies are not discussed in detail and still lack of practical tools. Besides, the existing method is not working stably when dealing with different versions of Windows. In this paper, we try to compare different memory acquisition methods and discuss their virtues and disadvantages. Then, the methodologies of FireWire-based memory acquisition are discussed. Finally, we give a practical implementation of FireWire-based acquisition tool that can work well with different versions of Windows without causing BSoD problems.
Zhang Lei Wang Lianhai Zhang Ruichao Zhang Shubui Zhou Yang
