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Due to the advancement of cloud computing, public key encryption with equality test has become a hot topic in the cryptography community. The notion was extended to the identity-based setting to obtain a new primitive, called identity-based encryption with equality test (IBEET). To the best of our knowledge, there are two categories of authorization mechanisms for IBEET: ciphertext-specified authorization and user-specified authorization. However, these authorizations are not applicable for some scenarios. Motivated by this, we propose in this paper a new primitive, called identity-based encryption with equality test and datestamp-based authorization mechanism (IBEET-DBA). In the primitive, the data owner can control the validity of trapdoor by embedding datestamp into it. The cloud server can only obtain the correct equivalence results on the ciphertexts which are generated within the valid period of trapdoor. In this paper, we formally define this primitive and its security notion. Moreover, we propose the first IBEET-DBA scheme and prove its security.

Public key encryption with equality test (PKEET) is an important cryptographic primitive for protecting users’ outsourced data in the cloud-based email systems. Due to the fact that it is required to deploy different authorization policies for the demand of dynamic privacy protection in the cloud-based email systems, Ma et al. recently presented a new related primitive, called public key encryption with equality test supporting flexible authorization (PKEET-FA). In their proposal, four types of authorization were considered to support different authorization policies. Their proposal is based on the bilinear pairings. However, as the basic operation of equality test, bilinear pairings are expensive operations compared with modular multiplications and modular inverses. Hence, it is desired to propose a new method for constructing efficient equality test with modular multiplications and modular inverses. In this paper, we present such a PKEET-FA scheme. Compared with Ma et al.’s, our proposal is (surprisingly) more efficient, especially in terms of equality test. Moreover, our proposal supports an additional type of authorization, called user-specific ciphertext-to-user (or user-specific user-to-ciphertext) level authorization. Hence, ours is more flexible than Ma et al.’s.

Recently, Tseng et al. proposed a new notion for identity-based signature (IBS) scheme to resist ephemeral secret leakage (ESL) attacks, called leakage-free identity-based signature (leakage-free IBS), and devised the first secure leakage-free IBS scheme. However, they only considered the situation of the leakage of ephemeral secrets used for generating the signatures. Notice that the private key extraction procedure is probabilistic as well in their scheme, that is, there are ephemeral secrets used by the key generation center to generate the signers’ private keys. It is practical to consider that if the adversary comprises these ephemeral secrets, then he can reveal the master key of the system. Therefore, it is desired to introduce a new security notion for the leakage-free IBS schemes to consider the ESL attacks on both private key extraction and signing procedures. In this paper, we present such security notion. Moreover, we propose two IBS schemes that are proved to be secure under the new security notion.

Rastegari et al. recently proposed a certificateless signcryption (CL-SC) scheme. They claimed that their scheme is the first secure CL-SC scheme, which captures the known session-specific temporary information security (KSSTIS), in the standard model. In this paper, we point out that their scheme is insecure, which implies that how to construct a secure CL-SC scheme with KSSTIS in the standard model is still an open problem.

In cloud environments, group data sharing has become a hot topic in recent years. How to share data securely and efficiently in cloud environments is an urgent problem to be solved. Recently, an anonymous and traceable group data sharing scheme was proposed by Shen et al. to address this issue. They constructed their scheme using a group signature scheme as the building block. In this comment, we discuss the security of their group signature scheme and point out that it does not achieve the anonymity which they claimed and give a corresponding attack.

The dendritic cell (DC)-regulatory T (Treg) system serves a leading role in the immunosuppression of the tumor microenvironment, which is not conducive to radiotherapy and chemotherapy treatment for lung cancer. The present study aimed to investigate the effect of oxymatrine (OMT) on the DC-Treg system in the tumor microenvironment in vitro and to examine its mechanism. The expressions of CD83 antigen, T-lymphocyte activation antigen CD86, CD11 antigen-like family member C and major histocompatibility complex II in DCs were increased upon treatment with 1 mg/ml OMT, as detected by flow cytometry. Following pretreatment with OMT, the DCs mediated the forkhead box protein P3 overexpression in primitive cluster of differentiation 4+ T cells at the protein and mRNA expression levels. The expression levels of anti-inflammatory factors, including interleukin (IL)-10, tumor growth factor-β, IL-35, and pro-inflammatory cytokines, including interferon-γ, IL-12 and IL-2, in the co-culture supernatant were increased as measured by ELISA. When DCs and DC-Tregs were co-cultured with cisplatin-resistant A549 cells, the proportion of apoptosis in the co-culture groups was increased under treatment with cisplatin, which was detected by Annexin V/propidium Iodide staining and western blotting. The present results suggested that OMT may promote the maturation of DCs, mediate the differentiation of T cells into Treg cells, and reverse the resistance of tumor cells to cisplatin in vitro. It was suggested that OMT is an important adjunct to chemotherapy through the regulation of antitumor responses.

Recently, Zhang et al. proposed a new anonymous hierarchical identity-based encryption (anonymous HIBE) over prime order groups to achieve both constant size private key and constant size ciphertext. Moreover, a double exponent technique was used to provide anonymity. They proved that their scheme is secure and anonymous against chosen plaintext attacks in the standard model. In this paper, we point out that their scheme is insecure.

In this paper, we present the concept of certificateless public key encryption with equality test (CL-PKEET), which integrates certificateless public key cryptography (CL-PKC) into public key encryption with equality test (PKEET) to solve the key escrow problem of identity-based encryption with equality test (IBEET). In the CL-PKEET scheme, the receiver first computes his private key with the receiver’s secret value and the partial private key generated by the key generation center (KGC). The trapdoor is generated with this private key. Then, using the trapdoor, the receiver authorizes the cloud server to test the equivalence between his ciphertexts and others’ ciphertexts. We formalize the system model and definition of CL-PKEET, propose the security models by considering four types of adversaries, and then present a concrete CL-PKEET scheme. Our proposal achieves the IND-CCA security against adversaries without trapdoor, and the OW-CCA security against adversaries with trapdoor. Furthermore, compared with IBEET and PKEET, our proposal which has the features of CL-PKC solves certificate management and key escrow problems simultaneously.

Public key encryption with equality test (PKEET) allows the cloud server to test whether two ciphertexts are generated on the same message. Recently, Lee et al. proposed a semi-generic approach for PKEET constructions by using the traditional public key encryption schemes. However, how to design a generic approach is still an open problem. In this paper, we propose a generic approach for PKEET constructions. Our approach can be easily extended to the identity-based setting. Compared with Lee et al.’s approach, ours is (surprisingly) more efficient. Moreover, we propose a new primitive, called signcryption with equality test (SCET). Compared with the traditional PKEET, SCET provides both confidentiality and authentication simultaneously.

In order to resolve the key escrow in identity-based scheme and the significant cost of using a PKI system in traditional public key scheme, the notion of certificateless public key cryptography (CL-PKC) was introduced. The first certificateless public key encryption scheme (CL-PKE) was proposed by Al-Riyami and Paterson, and then further schemes were developed. However, most of them are constructed from the bilinear pairing which is a time costing operation. In this paper, we construct an efficient CL-PKE scheme from RSA since RSA is the de facto Internet standard and is widely used in many applications. The security is based on Kilian–Petrank’s RSA assumption which is a variant of RSA.

The burgeoning functions of many microRNAs (miRs) have been well study in cancer. However, the level and function of miR-1205 in laryngeal squamous cell cancer remains unknown. In the current research, we validated that miR-1205 was notably downregulated in human laryngeal squamous cell carcinoma (LSCC) samples in comparison with tissues adjacent to LSCC, and correlated with T stage, lymph node metastasis, and clinical stage. Using Kaplan–Meier analysis indicates that high expression of miR-1205 has a favorable prognosis for patients with LSCC. Functional assays show that enforced miR-1205 expression attenuates the migration, growth, and invasion of LSCC cells. And E2F1 is verified to be a target of miR-1205, while E2F1 binds to miR-1205 promoter and transcriptionally inhibits miR-1205 expression. Overexpression of E2F1 reverses the inhibitory impacts of miR-1205 on LSCC cells in part. Importantly, E2F1 is abnormally increased in LSCC tissues, and its protein levels were inversely relevant to miR-1205 expression. High E2F1 protein level is in connection with clinical stage, T stage, lymph node metastasis, and poor prognosis. Consequently, reciprocal regulation of miR-1205 and E2F1 plays a crucial role in the progression of LSCC, suggesting a new miR-1205/E2F1-based clinical application for patients of LSCC.

Oxymatrine (OMT) has shown broad antitumor activities for the treatment of several types of cancers. However, little is known about its effect on anti-tumor immunity. Combination therapy is a potentially promising strategy of cancer to enhance anticancer activity, overcome drug resistance, and lower treatment failure rate. In the present study, we demonstrated that the combination of OMT with cisplatin (DDP) synergistically inhibited non-small cell lung cancer (NSCLC) cells growth when co-cultured with peripheral blood mononuclear cells in vitro. Furthermore, the combination of OMT with DDP significantly inhibited the growth of Lewis lung cancer (LLC) mouse xenograft tumors. Flow cytometry analysis revealed that OMT and DDP synergistically increase the CD8+/ regulatory T cells ratio and enhanced more CD8+ T cells secreted cytokines of IFN-γ, TNF-α, and IL-2 in vivo. Mechanistically, upregulation of miR-155 and downregulation of suppressor of cytokine signaling-1 (SOCS1) were confirmed as a target signaling pathway to positively regulate the anti-tumor response of CD8+ T cells. Overall, OMT in combination with DDP showed outstanding synergistic anti-tumor immunity, suggesting that this beneficial combination may offer a potential immunotherapy for NSCLC patients.

WEE1 is a tyrosine kinase that regulates G2/M cell cycle checkpoint and frequently overexpressed in various tumors. However, the expression and clinical significance of WEE1 in human laryngeal squamous cell carcinoma (LSCC) are still unknown. In this study, we found that WEE1 was highly expressed in LSCC tissues compared with adjacent normal tissues. Importantly, overexpression of WEE1 was correlated with T stages, lymph node metastasis, clinical stages and poor prognosis of LSCC patients. Furthermore, inhibition of WEE1 by MK-1775 induced cell growth inhibition, cell cycle arrest and apoptosis with the increased intracellular reactive oxygen species (ROS) levels in LSCC cells. Pretreatment with ROS scavenger N-acetyl-L-cysteine could reverse MK-1775-induced ROS accumulation and cell apoptosis in LSCC cells. MK-1775 also inhibited the growth of LSCC xenografts in nude mice. Altogether, these findings suggest that WEE1 is a potential therapeutic target in LSCC, and inhibition of WEE1 is the prospective strategy for LSCC therapy.

The Internet of Things (IoT) will be formed by smart objects and services interacting autonomously and in real-time. Recently, Alcaide et?al. proposed a fully decentralized anonymous authentication protocol for privacy-preserving IoT target-driven applications. Their system is set up by an ad-hoc community of decentralized founding nodes. Nodes can interact, being participants of cyberphysical systems, preserving full anonymity. In this study, we point out that their protocol is insecure. The adversary can cheat the data collectors by impersonating a legitimate user.

As the widespread deployment and usage of 802.11-based wireless local area networks (WLANs), Wi-Fi users are vulnerable to be attacked by a security threat called evil twins. The evil twin, a kind of rogue access points (RAPs), masquerades as a legitimate access point (AP) to lure users to connect it. Malicious adversaries can easily configure evil twins on a laptop to induce victim wireless users. The presence of such a threat continuously leads to significant loss of information. In this paper, we propose a passive client-side detection approach that allows users to independently identify and locate evil twins without any assistance from a wireless network administrator. Because of the forwarding behavior of evil twins, proposed method compares 802.11 data frames sent by target APs to users to determine evil twin attacks. We implemented our detection and location technique in a Python tool named ET-spotter. Through implementation and evaluation in our study, our algorithm achieves 96% accuracy in distinguishing evil twins from legitimate APs.

Steinwandt and Corona proposed a forward-secure identity-based non-interactive key distribution (ID-NIKD) scheme and proved its security, and then a forward-secure identity-based encryption (IBE) constructed from their forward-secure ID-NIKD scheme. In this study, attacks are presented to point out that their ID-NIKD scheme and IBE scheme are not forward-secure. We conclude that how to construct a forward-secure ID-NIKD scheme is still an open problem.

Recently, Islam and Li proposed the first certificateless signcryption scheme without ephemeral secret leakage (ESL) attack, called leakage-free certificateless signcryption (leakage-free CLSC) scheme. However, we point out in this paper that the confidentiality property is not captured in their proposal. Moreover, our attack adheres to the security model proposed in the original paper. On the other hand, the security models proposed by Islam and Li are insufficient. In fact, the ESL attack is not involved in the security models since the ephemeral secret is not returned to the adversary when CLSC-Signcryption query and Challenge are issued. Finally, we give the amended security models.

In this paper, some of the known definitions of the contrast of the Visual Cryptography Scheme (VCS) are shown to be inappropriate, and a new definition of the contrast based on our observations is proposed. It is also shown how our new definition of the contrast agreed with our observations.

Two common drawbacks of the visual cryptography scheme (VCS) are the large pixel expansion of each share image and the small contrast of the recovered secret image. In this paper, we propose a step construction to construct VCSOR and VCSXOR for general access structure by applying (2,2)-VCS recursively, where a participant may receive multiple share images. The proposed step construction generates VCSOR and VCSXOR which have optimal pixel expansion and contrast for each qualified set in the general access structure in most cases. Our scheme applies a technique to simplify the access structure, which can reduce the average pixel expansion (APE) in most cases compared with many of the results in the literature. Finally, we give some experimental results and comparisons to show the effectiveness of the proposed scheme.

Droste [CRYPTO’96] proposed a construction of threshold visual cryptography scheme (TVCS) under the visual cryptography model of Naor and Shamir, i.e. the visual cryptography model with the underlying operation OR. In this article, we give three extensions of TVCS. First, we prove that the TVCS proposed by Droste which was based on the OR operation is still a valid TVCS under the XOR operation, and then we propose a method to further reduce its pixel expansion. We then propose an interesting construction of TVCS with all shares being concolorous. Finally, we give a construction of threshold extended visual cryptography scheme (TEVCS) with the underlying operation OR or XOR. All of our schemes can be applied to the visual cryptography model introduced by Tuyls et al. (First Int. Conf. Security in Pervasive Computing 2004, International Patent with Application No.: PCT/IB2003/000261).

Pixel expansion is an important parameter for Visual Cryptography Schemes (VCS). However, most papers in the literature are dedicated to reduce pixel expansion on the pixel level, i.e. to reduce the number of subpixels that represent a pixel in the original secret image. It is quite insufficient since the final size of the transparencies of the VCS is affected not only by the number of the subpixels, but also by the size of the subpixels in the transparencies. However, reducing the size of the subpixels in the transparencies results in difficulties of alignment of the transparencies. In this paper, we consider the alignment problem in VCS, and prove that in order to visually recover the original secret image, it is not necessary to align the transparencies precisely. This study is restricted to the case when only one transparency is shifted.

This paper is to study a subclass of group-oriented cryptographic scheme: Many-to-one encryption and authentication scheme. The many-to-one encryption and authentication scheme is to solve a practical problem, i.e., the scenario that the number of the receivers is very small compared with the number of the senders and a receiver may serve millions of senders. Compared with the traditional methods, the burdens of the receiver and the KGC are reduced greatly. How to revoke a sender from his receiver's legitimate sender group is also proposed and it is efficient compared with some traditional methods. The proposed scheme is proven in the random oracle models. The computational complexity of our scheme is independent of the number of the senders. At the end of the paper, an example is given to show how to use our scheme in online software registration and update.

Most cheating immune visual cryptography schemes (CIVCS) are based on a traditional visual cryptography scheme (VCS) and are designed to avoid cheating when the secret image of the original VCS is to be recovered. However, all the known CIVCS have some drawbacks. Most usual drawbacks include the following: the scheme needs an online trusted authority, or it requires additional shares for the purpose of verification, or it has to sacrifice the properties by means of pixel expansion and contrast reduction of the original VCS or it can only be based on such VCS with specific access structures. In this study, the authors propose a new CIVCS that can be based on any VCS, including those with a general access structure, and show that their CIVCS can avoid all the above drawbacks. Moreover, their CIVCS does not care about whether the underlying operation is OR or XOR.

Visual cryptography scheme (VCS) is a kind of secret-sharing scheme which allows the encryption of a secret image into n shares that are distributed to n participants. The beauty of such a scheme is that, the decryption of the secret image requires neither the knowledge of cryptography nor complex computation. Colour visual cryptography becomes an interesting research topic after the formal introduction of visual cryptography by Naor and Shamir in 1995. The authors propose a colour (k, n)-VCS under the visual cryptography model of Naor and Shamir with no pixel expansion, and a colour (k, n)-extended visual cryptography scheme ((k, n)-EVCS) under the visual cryptography model of Naor and Shamir with pixel expansion the same as that of its corresponding black and white (k, n)-EVCS. Furthermore, the authors propose a black and white (k, n)-VCS and a black and white (k, n)-EVCS under the visual cryptography model of Tuyls. Based on the black and white schemes, the authors propose a colour (k, n)-VCS and a colour (k, n)-EVCS under the same visual cryptography model, of which the pixel expansions are the same as that of their corresponding black and white (k, n)-VCS and (k, n)-EVCS, respectively. The authors also give the experimental results of the proposed schemes, and compare the proposed scheme with known schemes in the literature.

In IEE Proceedings Communications, 2005, 152, (6), an efficient authenticated identity-based multicast scheme from bilinear pairing was proposed. Wang proved that the scheme is secure against the adversary who can forge a ciphertext, but it is shown that their scheme is not secure against an inside forger.