Symmetric Public-Key Encryption

Public-key encryption would seem to be inherently asymmetric. in that only messages sent to a user can be encrypted using his public key. We demonstrate that the use of interactive protocols for sending encrypted messages enables a symmetric use of public keys; we give cryptographic protocols for the following tasks: 1. Probabilistic encryption, using the same public key, both of messages that are sent to a particular user as well as of messages that the user sends to others, without compromising the key. We propose a public-key cryptosystem based on these protocols which has only one key, owned by a cryptographic server. 2. Authentication both of the sender and of the receiver of a probabilistically encrypted message. 3. Probabilistic encryption which is provably secure against both chosen-message and chosen-ciphertext attack

The Myth of Superiority of American Encryption Products

Encryption software and hardware use sophisticated mathematical algorithms to encipher a message so that only the intended recipient may read it. Fearing that criminals and terrorists will use encryption to evade authorities, the United States now restricts the export of encryption products with key lengths of more than 56 bits. The controls are futile, because strong encryption products are readily available overseas. Foreign-made encryption products are as good as, or better than, U.S.-made products. U.S. cryptographers have no monopoly on the mathematical knowledge and methods used to create strong encryption. Powerful encryption symmetric-key technologies developed in other countries include IDEA and GOST. Researchers in New Zealand have developed very strong public-key encryption systems. As patents on strong algorithms of U.S. origin expire, researchers in other countries will gain additional opportunities to develop strong encryption technology based on those algorithms

Assessment of Work Pedestal on RSA in Text Cryptographic System

Cryptography is a Greek word, crypto signifies ‘hidden or covered up’ and graphy means ‘study’. The conversion of plain text to cipher text is called as encryption and changing the cipher text to plain text is called as decryption. Cryptographic algorithm further divides in symmetric cryptography and asymmetric cryptography. Symmetric cryptography has only one key for both encryption and decryption, this key is called as secret key or private key. Asymmetric cryptography has two keys, one key is used for encryption this key is called public key and other key is used for decryption this key is called as private key. In this paper, we survey on the customized advance of RSA by using manifold of public keys and prime numbers. This algorithm is providing more secure communication over the network of text files

Public-Key Encryption with Delegated Search

In public-key setting, Alice encrypts email with public key of Bob, so that only Bob will be able to learn contents of email. Consider scenario when computer of Alice is infected and unbeknown to Alice it also embeds malware into message. Bob's company, Carol, cannot scan his email for malicious content as it is encrypted so burden is on Bob to do scan. This is not efficient. We construct mechanism that enables Bob to provide trapdoors to Carol such that Carol, given encrypted data and malware signature, is able to check whether encrypted data contains malware signature, without decrypting it. We refer to this mechanism as Public-Key Encryption with Delegated Search SPKE.\ud \ud We formalize SPKE and give construction based on ElGamal public-key encryption (PKE). proposed scheme has ciphertexts which are both searchable and decryptable. This property of scheme is crucial since entity can search entire content of message, in contrast to existing searchable public-key encryption schemes where search is done only in metadata part. We prove in standard model that scheme is ciphertext indistinguishable and trapdoor indistinguishable under Symmetric External Diffie-Hellman (sxdh) assumption. We prove also ciphertext one-wayness of scheme under modified Computational Diffie-Hellman (mcdh) assumption. We show that our PKEDS scheme can be used in different applications such as detecting encrypted malwares and forwarding encrypted emails

A Comprehensive Cloud Security Model with Enhanced Key Management, Access Control and Data Anonymization Features

A disgusting problem in public cloud is to securely share data based on fine grained access control policies and unauthorized key management. Existing approaches to encrypt policies and data with different keys based on public key cryptosystem are Attribute Based Encryption and proxy re-encryption. The weakness behind approaches is: It cannot efficiently handle policy changes and also problem in user revocation and attribute identification.  Even though it is so popular, when employed in cloud it generate high computational and storage cost. More importantly, image encryption is some out complex in case of public key cryptosystem. On the publication of sensitive dataset, it does not preserve privacy of an individual. A direct application of a symmetric key cryptosystem, where users are served based on the policies they satisfy and unique keys are generated by Data Owner (DO). Based on this idea, we formalize a new key management scheme, called Symmetric Chaos Based key Management (SCBKM), and then give a secure construction of a SCBKM scheme called AS-Chaos. The idea is to give some secrets to Key Manager (KM) based on the identity attributes they have and later allow them to derive actual symmetric keys based on their secrets. Using our SCBKM construct, we propose an efficient approach for fine-grained encryption-based access control for data stored in untrusted cloud storage

Quantum asymmetric cryptography with symmetric keys

Based on quantum encryption, we present a new idea for quantum public-key cryptography (QPKC) and construct a whole theoretical framework of a QPKC system. We show that the quantum-mechanical nature renders it feasible and reasonable to use symmetric keys in such a scheme, which is quite different from that in conventional public-key cryptography. The security of our scheme is analyzed and some features are discussed. Furthermore, the state-estimation attack to a prior QPKC scheme is demonstrated.Comment: 8 pages, 1 figure, Revtex

New Method in Encryption

Encryption in this paper includes the use of  three values which they are the two shadows values of a base value, and the base value is attained from the three shadows values . Encryption  based on two keys was proposed to increase the security of single encryption. We introduce a novel combination of  asymmetric (two public –key) and symmetric ( private-key). Public key and private key  involves odd and even whole values (first shadow value , second shadow value and third shadow value) . shadows values are multiplied making a product value and the value of 1 is subtracted from the produce value, The base value is along with the chosen shadows values ,then we employ  values to find public key to encrypt message and private key to decrypt the encrypted message , as well as introduce new ideal to conclude the private key from the public key in two method ,first method determine the values agreed on some of them between the sender and the recipient . Second raised prime number to different value. Key words: Encryption,  shadows value,  public key, private ke

A New Image Encryption Algorithm Based Slicing and Displacement Followed By Symmetric and Asymmetric Cryptography Technique

This paper titled “A New Algorithm for Image Encryption Based on Slicing, Displacement Followed by Symmetric Encryption” is proposed for image encryption by studding the principle of the image encryption algorithm. In this, a new hybrid image encryption algorithm is proposed by analyzing the principle of the encryption algorithm based on the combination of symmetric and asymmetric encryption. The experimental results based on combination of symmetric and asymmetric encryption will approve the effectiveness of the proposed concept, and the combination of symmetric and asymmetric encryption will show large variation in key space and provide high-level security. Proposed algorithm will support to integrity, authorization, accuracy of images which is transmitting in public network. As we know that, an image-based data requires more effort during encryption and decryption. This research introduces a block-based algorithm which is the combination of “Slicing and Displacement of RGB value of a Pixel” and “Block Cipher” base image encryption algorithm. The original image was divided into four equal parts, where each part of image will rearranged into displacement of RGB value of a pixel and then resultant image will divided into pixel blocks. Read binary value of pixel blocks. This binary value will be process by encryption process through binary value of selected key. Now finally encrypted image will be produced. This process will repeat on each parts of image. After that each part will be combining and produce final cipher image. Encryption key will also encrypted by asymmetric key concept so key exchanging problem will not occur in this system. The Proposed Architecture for encryption and decryption of an image using suitable user-defined key is developed. The cipher image generated by this method can be very in size as the original image due to image scaling to make 128 bits block at a time and is suitable for practical use in the secure transmission of confidential information over the Internet. DOI: 10.17762/ijritcc2321-8169.15053