The National Institute of Standards and Technology (NIST) provides cryptographic key management guidance for defining and implementing appropriate key management procedures, using algorithms that adequately protect sensitive information, and planning ahead for possible changes in the use of cryptography because of algorithm breaks or the availability of more powerful computing techniques. NIST Special Publication (SP) 800-57 Part 1 includes a general approach for transitioning from one algorithm or key length to another. This Recommendation (SP 800-131A Revision 1) provides more specific guidance for transitions to the use of stronger cryptographic keys and more robust algorithms.

Transitions: Recommendation for Transitioning the Use of Cryptographic Algorithms and Key Lengths

Chaotic dynamics is widely used to design pseudo-random number generators and for other applications such as secure communications and encryption. This paper aims to study the dynamics of discrete-time chaotic maps in the digital (i.e., finite-precision) domain. Differing from the traditional approaches treating a digital chaotic map as a black box with different explanations according to the test results of the output, the dynamical properties of such chaotic maps are first explored with a fixed-point arithmetic, using the Logistic map and the Tent map as two representative examples, from a new perspective with the corresponding state-mapping networks (SMNs). In an SMN, every possible value in the digital domain is considered as a node and the mapping relationship between any pair of nodes is a directed edge. The scale-free properties of the Logistic map's SMN are proved. The analytic results are further extended to the scenario of floating-point arithmetic and for other chaotic maps. Understanding the network structure of a chaotic map's SMN in digital computers can facilitate counteracting the undesirable degeneration of chaotic dynamics in finite-precision domains, helping also classify and improve the randomness of pseudo-random number sequences generated by iterating chaotic maps.

Dynamic Analysis of Digital Chaotic Maps via State-Mapping Networks

Network security is an important aspect of information sharing. Attempts have been made to remove various insecurities over internet. For this, many technological implementations and security policies have been developed. The amount of data, transferred, is not a factor. The basic factor is, how much security, the channel provides while transmitting data. Cryptography is one such technique, which allows secure data transmission without losing its confidentiality and integrity. Based on the key distribution, cryptography is further classified into two major types-Symmetric Key Cryptography and Asymmetric Key Cryptography. In this paper, we have surveyed the traditional algorithms, along with the proposed algorithms based on their pros and cons, related to Symmetric and Asymmetric Key Cryptography. We have also compared the importance of both these cryptographic techniques. The proposed algorithms proved to be highly efficient in their respective grounds but there are certain areas that remained open, related to these algorithms, and have not yet been thoroughly discussed. This paper also presents an appropriate future scope related to these open fields.

A comparative survey of Symmetric and Asymmetric Key Cryptography

If you really want to be smarter, reading can be one of the lots ways to evoke and realize. Many people who like reading will have more knowledge and experiences. Reading can be a way to gain information from economics, politics, science, fiction, literature, religion, and many others. As one of the part of book categories, foundations of soft case based reasoning always becomes the most wanted book. Many people are absolutely searching for this book. It means that many love to read this kind of book.

Foundations Of Soft Case Based Reasoning

This paper suggests a unique image encryption scheme based on key-based block ciphering followed by shuffling of ciphered bytes with variable-sized blocks, which makes this scheme substantially robust compared to other contemporary schemes available. Another distinguishing feature of this scheme is the usage of variable-sized key streams for consecutive blocks. Based on the elementary cellular automata with chaotic tent map, distinct key streams are used to cipher individual blocks. In the subsequent step, the bytes of the ciphered block so obtained are further shuffled to make the scheme more diffused. The block size varies with the varying key stream, which is again dependent on the preceding key stream as well as the plain image. It needs to be mentioned that the size of the first block and the key stream are generated from a 64-byte secret key and the plain image. Values of correlation and the number of pixel change rate between the original and the encrypted images are 0.000479 and 99.620901, respectively. Both of the above results along with other relevant experimental results strongly establish the robustness of the proposed scheme.

A robust image encryption scheme using chaotic tent map and cellular automata

In recent years, Quantum Electronics and Reversible Logic have emerged as a major area of research having applications in low power CMOS circuits, cryptography, optical computing and nanotechnology. The fact that classical logic gates such as AND, OR, XOR etc., barring the NOT gate, cannot predict the input given the output and hence generate heat due to information loss, has given rise to the concept of reversible logic. In this paper, a new reversible 4 * 4 “SCG” gate has been proposed which is being used to realize the classical set of logic gates in the reversible domain. The most promising fact of the proposed gate is that a single SCG gate can be used to realize a reversible Full Adder/Subtractor circuit or a single bit reversible Comparator. It has been shown that the Full Adder/Subtractor and the single bit Comparator using the proposed gate is much better and optimized in terms of number of garbage outputs and the number of reversible gates used in comparison to the existing counterparts in literature. Further efficient Reversible Parallel Adder/Subtractor circuits and Match Logic have been designed using the proposed SCG gate. Also a 4-bit digital comparator has been designed by cascading a series of single bit comparators using SCG gate. General Terms Architecture, Logic Design, Reversible Logic Gate.

https://research.ijcaonline.org/volume31/number9/pxc3875372.pdf

Realization of a Novel Reversible SCG Gate and its Application for Designing Parallel Adder/Subtractor and Match Logic

Image authentication has achieved a sharp attention now a day due to broad availability of internet services. Maldistribution and illegal copying of image, volatiles the authenticity of image-ownership. In this regard we’ve already proposed different fragile color image watermarking frameworks for embedding a color watermark within a color host image. In current communication we are proposing technique which will ensure the complete authentication of ownership in a dynamic manner. The proposed framework will form the watermark from the host image itself by combining the unique zone of the host image, and then it will be embedded to the host image with our already reported LSB scheme. In proposed watermarking framework, it allows a user with an appropriate secret key and a hash function to verify the authencity, integrity and ownership of an image. If a forger performs the watermark extraction with an incorrect key and inappropriate hash function, the user obtains an image that resembles noise. In this manner we are providing an integrated solution for ownership authentication where the watermark is unique for that particular host image, thus the authentication is ensured in an efficient way. At the watermark extraction end, we’ve used blind extraction method, i.e., neither the host image nor the watermark image is required at the time of watermark extraction.

A Dynamic Watermarking Scheme for Color Image Authentication

This paper presents an efficient image encryption scheme based on permutation followed by diffusion, where both of these phases use 2-d Sine logistic modulation map (SLMM) with different initial values. In addition, diffusion uses another map as 1-d Logistic chaotic map (LCM). The initial values of these chaotic maps are obtained from an external key of 64 bytes along with 32-byte hash value from the corresponding plain-image to incorporate plain-text sensitivity. Initially, confusion of the plain-image is implemented by applying row-level and column-level permutations. Then, this permuted image is used for subsequent diffusion, applied on block-level considering block size of 64 bytes. This diffusion process is accomplished by overlaying with chaotic matrix derived from LCM, followed by substitution of those overlaid bytes by DNA encoding along with SLMM to attain an encrypted image with an entropy nearly 8. Furthermore, all the chaotic values generated from the aforementioned maps are highly sensitive on the key as well as on the plain-image. This scheme is thoroughly verified on different sized plain-images with modern statistical analyses to prove the robustness of this scheme. Eventually, comparison with other schemes reinforces its competence and suitability to implement it in real-time system.

An efficient block-level image encryption scheme based on multi-chaotic maps with DNA encoding

From thousands of years back our predecessors have invented several ways of passing information in hidden form with other objects like papyrus scroll, cryptex etc. As decades crossed through earth's vein we are getting matured and invented several steganographic systems for message passing. The availability of internet in every corner of the universe forced the user of steganographic systems to invent and implement a better secured algorithm for encryption and decryption of text. In this paper we are going to propose a framework for embed text string into digital color images and the text that is embedded is perceptually invisible to Human Visual System (HVS). Many text steganographic systems are available that are passing the text with digital media as a form of message digest that can be hacked easily. Here our algorithm supersedes the conventional algorithms. Instead of forming message digest first a 32-bit secret key will be provided by the encrypter and that will be applied on the text with a hash function. That gives us a pseudo byte stream. Now we embed that pseudo byte stream directly to image pixels and after that the text will become the physical property of the encrypted image. On the other end if an intruder tries to perform the extraction of the text with a wrong secret key, he will not be succeeded. In the proposed framework the information of Red (R), Green (G) & Blue (B) values of the pixels of the host color image are retrieved. Subsequently the text is converted into byte stream with respect to the ASCII values of the characters present in the text. Triggering that byte stream with the secret key and hash function produces the pseudo byte stream. Each bit of this byte stream will be embedded in to the LSBs of RGB bytes of the image pixels that ensure the invisibility of text in the encrypted image. The extraction of the text is blind i.e., except the secret key nothing is needed for text decryption.

A secured key-based digital text passing system through color image pixels

In today’s scenario many audio/voice files are needed to be transmitted over internet for various important purposes. So protection of these files is an important issue. Efficient cryptographic methods are there to protect data but every thing depends on the protection of encryption key. That leads to single point failure. To overcome this drawback shared cryptography becomes more popular. Here we are suggesting a novel secret sharing scheme which employs simple graphical masking method, performed by simple ANDing for share generation and reconstruction can be done by performing simple ORing the qualified set of legitimate shares. Not only that, the generated shares are compressed and each share contains partial secret information, that leads to added protection to the secret and reduced bandwidth requirement for transmission.

https://www.ijcaonline.org/volume26/number8/pxc3874305.pdf

Atal Chaudhuri

Papers

Realization of a Novel Reversible SCG Gate and its Application for Designing Parallel Adder/Subtractor and Match Logic

A Dynamic Watermarking Scheme for Color Image Authentication

An efficient block-level image encryption scheme based on multi-chaotic maps with DNA encoding

A secured key-based digital text passing system through color image pixels

Shared Cryptography with Embedded Session Key for Secret Audio