搜索结果：Encrypt

Traditional video encryption methods protect video content by encrypting each frame individually. However, in resource-constrained environments, this approach consumes significant computational resources. To overcome this challenge, this paper proposes a novel method called “Encrypt a story (EAS)”, which aims to enhance encryption efficiency by focusing on encrypting specific segments of the video rather than encrypting each frame. The EAS refers to selecting segments in the time dimension of the video that contain important information or key events for encryption. This method leverages video segmentation techniques to focus encryption efforts on continuous key frames, significantly reducing the consumption of computational resources. To address the need for a large number of key streams during the encryption process, this paper proposes a discrete sinusoidal memristive Rulkov neuron map (DSM-RNM). Through attractor analysis, complexity comparison, Lyapunov exponent, and NIST tests, we validated its ability to generate high-performance pseudorandom sequences, which significantly enhances the security of the encryption algorithm. Notably, the DSM-RNM is shown to exhibit a phenomenon of infinitely coexisting attractors. Furthermore, by constructing a digital circuit to capture the attractors of the DSM-RNM, its potential for industrial applications is demonstrated. Evaluation results show that the EAS saves approximately 90% of the time while ensuring security, exhibiting strong practicality and efficiency

Logic Encryption is one of the most popular hardware security techniques which can prevent IP piracy and illegal IC overproduction. It introduces obfuscation by inserting some extra hardware into a design to hide its functionality from unauthorized users. Correct functionality of an encrypted design depends upon the application of correct keys, shared only with the authorized users. In the recent past, extensive efforts have been devoted in extracting the secret key of an encrypted design. At the same time, several countermeasures have also been proposed by the research community to thwart different state-of-the-art attacks on logic encryption. However, most of the proposed countermeasures fail to prevent the powerful SAT attack. Although a few researchers have proposed different solutions to withstand SAT attack, those solutions suffer from several drawbacks such as high design overheads, low output corruptibility, and vulnerability against removal attack. Almost all the known logic encryption strategies are vulnerable to scan based attack. In this paper, we propose a novel encryption technique called Encrypt Flip-Flop, which encrypts the outputs of selected flip-flops by inserting multiplexers (MUX). The proposed strategy can thwart all the known attacks including SAT and scan based attacks. The scheme has low design overhead and implementation complexity. Experimental results on several ISCAS'89 and ITC'99 benchmarks show that our proposed method can produce reasonable output corruption for wrong keys.

Claude Mythos Preview discovered new attacks in testing against weakened cryptographic algorithms, which protect online financial transactions, private communications and more

Encryption can provide strong security for sensitive data against inside and outside attacks. This is especially true in the “Database as Service” model, where confidentiality and privacy are important issues for the client. In fact, existing encryption approaches are vulnerable to a statistical attack because each value is encrypted to another fixed value. This paper presents a novel database encryption scheme called MV-OPES (Multivalued — Order Preserving Encryption Scheme), which allows privacy-preserving queries over encrypted databases with an improved security level. Our idea is to encrypt a value to different multiple values to prevent statistical attacks. At the same time, MV-OPES preserves the order of the integer values to allow comparison operations to be directly applied on encrypted data. Using calculated distance (range), we propose a novel method that allows a join query between relations based on inequality over encrypted values. We also present techniques to offload query execution load to a database server as much as possible, thereby making a better use of server resources in a database outsourcing environment. Our scheme can easily be integrated with current database systems as it is designed to work with existing indexing structures. It is robust against statistical attack and the estimation of true values. MV-OPES experiments show that security for sensitive data can be achieved with reasonable overhead, establishing the practicability of the scheme.

As more sensitive data is shared and stored by third-party sites on the Internet, there will be a need to encrypt data stored at these sites. One drawback of encrypting data, is that it can be selectively shared only at a coarse-grained level (i.e., giving another party your private key). We develop a new cryptosystem for fine-grained sharing of encrypted data that we call Key-Policy Attribute-Based Encryption (KP-ABE). In our cryptosystem, ciphertexts are labeled with sets of attributes and private keys are associated with access structures that control which ciphertexts a user is able to decrypt. We demonstrate the applicability of our construction to sharing of audit-log information and broadcast encryption. Our construction supports delegation of private keys which subsumesHierarchical Identity-Based Encryption (HIBE).

In several distributed systems a user should only be able to access data if a user posses a certain set of credentials or attributes. Currently, the only method for enforcing such policies is to employ a trusted server to store the data and mediate access control. However, if any server storing the data is compromised, then the confidentiality of the data will be compromised. In this paper we present a system for realizing complex access control on encrypted data that we call ciphertext-policy attribute-based encryption. By using our techniques encrypted data can be kept confidential even if the storage server is untrusted; moreover, our methods are secure against collusion attacks. Previous attribute-based encryption systems used attributes to describe the encrypted data and built policies into user's keys; while in our system attributes are used to describe a user's credentials, and a party encrypting data determines a policy for who can decrypt. Thus, our methods are conceptually closer to traditional access control methods such as role-based access control (RBAC). In addition, we provide an implementation of our system and give performance measurements.

In this paper, we propose a multiple images simultaneous encryption scheme by encrypting the orbital angular momentum (OAM) holography with ghost imaging. By controlling the topological charge of the incident OAM light beam on the OAM-multiplexing hologram, different images can be selectively obtained for ghost imaging (GI). Followed by the random speckles illumination, the bucket detector values in GI are obtained and then considered as the ciphertext transmitted to the receiver. The authorized user can distill the correct relationship between the bucket detections and the illuminating speckle patterns with the key and the additional topological charges, so that each holographic image can be successfully recovered, while the eavesdropper can not obtain any information about the holographic image without the key. The eavesdropper even can not get clear holographic image when all the key is eavesdropped but without topological charges. The experimental results show that the proposed encryption scheme has a higher capacity for multiple images because there is no theoretical topological charge limit for the selectivity of OAM holography, and the results also show that the proposed encryption scheme is more secure and has a stronger robustness. Our method may provide a promising avenue for multi-image encryption and has the potential for more applications.

With the proliferation of digital images over open networks, secure and efficient encryption schemes are imperative for safeguarding image privacy. This paper proposes a novel 5-stage image encryption algorithm adhering to Shannon’s confusion and diffusion paradigm. In the first stage, Langton’s Ant is employed to induce chaos and perturb the pixel distribution of the original image. The second and fourth stages apply Mersenne Twister generated keys to confuse the image via XOR operations. An S-box substitution is utilized in the third stage to disrupt pixel statistical properties. Finally, Arnold’s Cat map further scrambles and diffuses the pixel positions over the image. Extensive security analyses reveal the algorithm’s robustness against various attacks such as visual, entropy, brute-force, statistical and differential attacks. Additionally, it successfully passes the NIST SP 800-22 test suite. Performance results demonstrate the proposed algorithm’s efficacy for real-time secure image transmission with low computational overheads. The algorithm’s security level combined with high-speed performance makes it well-suited for practical image encryption applications.

Simple Sign & Encrypt, by itself, is not very secure. Cryptographers know this well, but application programmers and standards authors still tend to put too much trust in simple Sign-and-Encrypt. In fact, every secure e-mail protocol, old and new, has codified naive Sign & Encrypt as acceptable security practice. S/MIME, PKCS#7, PGP, OpenPGP, PEM, and MOSS all suffer from this flaw. Similarly, the secure document protocols PKCS#7, XML-Signature, and XML-Encryption suffer from the same flaw. Naive Sign & Encrypt appears only in file-security and mailsecurity applications, but this narrow scope is becoming more important to the rapidly-growing class of commercial users. With file- and mail-encryption seeing widespread use, and with flawed encryption in play, we can expect widespread exposures.

This paper describes an on-die lightweight nanoAES hardware accelerator, fabricated in 22 nm tri-gate high-k/metal-gate CMOS, targeted for ultra-low power symmetric-key encryption and decryption on mobile SOCs. Compared to conventional 128 bit AES implementations, this design uses a single 8 bit Sbox circuit along with ShiftRows byte-order data processing to compute all AES rounds in native GF(2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sup> ) <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> composite-field. This approach along with a serial-accumulating MixColumns circuit, area-optimized encrypt and decrypt Galois-field polynomials and integrated on-the-fly key generation circuit results in a compact encrypt/decrypt layout occupying 2200/2736 μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and lowest-reported gate count of 1947/2090 respectively, while achieving: (i) maximum operating frequency of 1.133 GHz and total power consumption of 13 mW with leakage component of 500 μW, measured at 0.9 V, 25 °C, (ii) nominal AES-128 encrypt/decrypt throughput of 432/671 Mbps respectively, with peak energy-efficiency of 289 Gbps/W measured at near-threshold operation of 430 mV (11 ×higher than previously reported implementations), (iii) encrypt/decrypt latencies of 336/216 cycles and total energy consumption of 3.9/2.5 nJ respectively, (iv) wide operating supply voltage range with robust sub-threshold voltage performance of 45 Mbps, 170 μW, measured at 340 mV, 25 °C and (v) first-reported Galois-field polynomial-based micro-architectural co-optimization, resulting in distinct area-optimized encrypt and decrypt polynomials with up to 9% area reduction at iso-performance.

We have analyzed the hardware full-disk encryption of several solid state drives (SSDs) by reverse engineering their firmware. These drives were produced by three manufacturers between 2014 and 2018, and are both internal models using the SATA and NVMe interfaces (in a M.2 or 2.5" traditional form factor) and external models using the USB interface. In theory, the security guarantees offered by hardware encryption are similar to or better than software implementations. In reality, we found that many models using hardware encryption have critical security weaknesses due to specification, design, and implementation issues. For many models, these security weaknesses allow for complete recovery of the data without knowledge of any secret (such as the password). BitLocker, the encryption software built into Microsoft Windows will rely exclusively on hardware full-disk encryption if the SSD advertises support for it. Thus, for these drives, data protected by BitLocker is also compromised. We conclude that, given the state of affairs affecting roughly 60% of the market, currently one should not rely solely on hardware encryption offered by SSDs and users should take additional measures to protect their data.

In this paper, the author propose a method, SD-EI, for image encryption, which basically has two stages: 1) In first stage, each pixel of image is converted to its equivalent eight bit binary number and in that eight bit number, the number of bits, which are equal to the length of password are rotated and then reversed; 2) In second stage, extended hill cipher technique is applied by using involutory matrix, which is generated by same password used in second stage of encryption to make it more secure. The technique presented in this paper is very good for encrypting any type of images, and from the encrypted image it is very difficult to extract the real image without proper authorization and algorithm implementation. The proposed approach is implemented for different images and the results were very satisfactory. The proposed technique, SD-EI, can be implemented by any person or organization to encrypt images, which are to be kept secret, or can encrypt the images, where data (messages) are already hidden using steganography.

As optical systems are diffraction limited, it is not possible to encrypt in a single step texts containing a large amount of characters. We overcome this situation by separately encrypting several characters, along with a multiplexing procedure to obtain an encrypted keyboard. The experimental application is performed in a joint transform correlator architecture and using digital holography. We combine the different characters into a keyboard encrypted with a single phase mask together with a selection-position key that gives the right sequence to recover safe encrypted messages. The multiplexing operation we suggest is advantageous in the sense that the technique enables processing of messages that otherwise the optical system could not process in a single step. We also employ a repositioning technique to prevent both the natural background noise over recovered characters and the possible cross talk. The lack of any single key avoids the correct message recovery. Experimental results are presented to show the feasibility of our proposal, representing an actual application of the optical encrypting protocols.

Let's Encrypt is a free, open, and automated HTTPS certificate authority (CA) created to advance HTTPS adoption to the entire Web. Since its launch in late 2015, Let's Encrypt has grown to become the world's largest HTTPS CA, accounting for more currently valid certificates than all other browser-trusted CAs combined. By January 2019, it had issued over 538 million certificates for 223 million domain names. We describe how we built Let's Encrypt, including the architecture of the CA software system (Boulder) and the structure of the organization that operates it (ISRG), and we discuss lessons learned from the experience. We also describe the design of ACME, the IETF-standard protocol we created to automate CA-server interactions and certificate issuance, and survey the diverse ecosystem of ACME clients, including Certbot, a software agent we created to automate HTTPS deployment. Finally, we measure Let's Encrypt's impact on the Web and the CA ecosystem. We hope that the success of Let's Encrypt can provide a model for further enhancements to the Web PKI and for future Internet security infrastructure.

In modern operating systems, cryptographic file systems can protect confidential data from unauthorized access. However, once an authorized process has accessed data from a cryptographic file system, the data can appear as plaintext in the unprotected virtual memory backing store, even after system shutdown. The solution described in this paper uses swap encryption for processes in possession of confidential data. Volatile encryption keys are chosen randomly, and remain valid only for short time periods. Invalid encryption keys are deleted, effectively erasing all data that was encrypted with them. April 25, 2000 Center for Information Technology Integration University of Michigan 519 West William Street Ann Arbor, MI 48103-4943 Encrypting Virtual Memory Niels Provos Center for Information Technology Integration University of Michigan provos@citi.umich.edu Abstract In modern operating systems, cryptographic file systems can protect confidential data from unauthorized access....

During the last decades, information security has become a major issue. Encrypting and decrypting data have recently been widely investigated and developed because there is a demand for a stronger encryption and decryption which is very hard to crack. Cryptography plays major roles to fulfilment these demands. Nowadays, many of researchers have proposed many of encryption and decryption algorithms such as AES, DES, RSA, and others. But most of the proposed algorithms encountered some problems such as lack of robustness and significant amount of time added to packet delay to maintain the security on the communication channel between the terminals. In this paper, the security goals were enhanced via "A New Approach for Complex Encrypting and Decrypting Data" which maintains the security on the communication channels by making it difficult for attacker to predicate a pattern as well as speed of the encryption / decryption scheme.