While instant messaging systems bring convenience to people's lives and work, they also make it easier for malicious users to discuss and plot illegal activities. Therefore, determining how to balance the privacy protection requirements of user communication in the network with the authorized monitoring requirements of law enforcement agencies (LEAs) is a meaningful task. To solve this problem, a new tripartite authenticated key agreement (Tri-AKA) protocol and a session key escrow scheme based on threshold cryptography and the new Tri-AKA protocol were proposed. In the proposed scheme, the LEA participates as a normal user in the key agreement process of two users and uses (t, n) threshold cryptography to share its ephemeral private key with n key escrow agents (KEAs). When necessary, the LEA can combine t KEAs to recover the specified session key and decrypt the communications, thereby preventing malicious administrators in the LEA from arbitrarily monitoring user communications. Finally, we proved the security of the proposed Tri-AKA protocol under the Computational Diffie-Hellman (CDH) assumption with the Random Oracle Model and the security of the proposed key escrow scheme under the Elliptic Curve Discrete Logarithm (ECDL) assumption. Analysis of our session key escrow scheme and comparison with other schemes show that our scheme can avoid the “once monitor, monitor forever” scenario and achieve fine-grained control in each session. Moreover, our scheme has low storage overhead for each KEA.

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Key Escrow Protocol Based on a Tripartite Authenticated Key Agreement and Threshold Cryptography

The safety of keys is the Achilles' heel of cryptography. A key backup at an escrow service lowers the risk of loosing the key, but increases the danger of key disclosure. We propose Recoverable Encryption (RE) schemes that alleviate the dilemma. RE encrypts a backup of the key in a manner that restricts practical recovery by an escrow service to one using a large cloud. For example, a cloud with ten thousand nodes could recover a key in at most 10 minutes with an average recovery time of five minutes. A recovery attempt at the escrow agency, using a small cluster, would require seventy days with an average of thirty five days. Large clouds have become available even to private persons, but their pay-for-use structure makes their use for illegal purposes too dangerous. We show the feaibility of two RE schemes and give conditions for their deployment.

/pdf/recoverable-encryption-through-a-noised-secret-over-a-large-6l998yn6o3.pdf

Recoverable encryption through a noised secret over a large cloud

Secure-channel establishment allows two endpoints to communicate confidentially and authentically. Since they hide all data sent across them, good or bad, secure channels are often subject to mass surveillance in the name of (inter)national security. Some protocols are constructed to allow easy data interception . Others are designed to preserve data privacy and are either subverted or prohibited to use without trapdoors.

How to (Legally) Keep Secrets from Mobile Operators

The known key escrow scheme requires equal number in key recover escrow side.This paper proposes a new key escrow scheme.In recovering session key,any assigned number of escrow side is allowable.When increasing,reducing and changing the member of escrow side,it is not necessary to modify the storing key part,and no more than 4n+1 (n is positive integer) RSA operations are needed respectively for key split or key recover.

A Key Escrow Scheme for Escrow Agency of Arbitrary Number

This work presents solution to the problem of optimal financial assets management and an escrow account usage in building company productiveness in the Russian Federation. A mathematical model of financial assets management process is made to increase implementation cost-effectiveness of a housing construction project. The model enables us to calculate a sales strategy which provides the lowest loan rate in order to minimize an interest rate paid by the building company. According to the monthly construction project funding schedule, the mathematical model helps to set the best possible escrow account balance by means of sales price and volume. The mathematical instrument, that is used to analyze factors of productiveness and profit growth in building industry, enables the building company to track current financial flows in real time, as well as to optimize summarizing financial indicators. Financial assets return calculations are exemplified by an average building company of the Udmurt Republic, the region of Russia where house building grows actively. The calculations of optimizing financial funds for 1.5-years long and 3-years long projects are also illustrated in this article.

https://link.springer.com/content/pdf/10.1007%2F978-3-030-65283-8_35.pdf

Optimization of Financial Flows in a Building Company Using an Escrow Account in the Russian Federation

To combat crime and terrorist organizations, government expects to monitor the suspicious communication but the leak of personal privacy is a common problem. Assuming that there are two Escrow Agent groups (Escrow party), one is designated by the government, while the other is unofficial. The two groups can achieve mutual supervision and dependence, thus implementing monitoring for users by the cooperation rather than by only a single one. If the number of the mutual participation is less than the required threshold number, the monitoring cannot be achieved. Therefore, an equation set corresponding to the specific program can be constructed, for example, multiply i th equation and j th equation to get an (i+j) th equation. As long as this kind of equation set is established, various key escrow schemes involved by several Escrow Agent groups can be constructed. Nowadays, the increasing political, economic, and cultural exchanges all over the world will lead to more and more transnational crime and terrorist attacks, so this program can be adapted to the multinational (or multi-organization) key escrow cooperation. Streszczenie. Analizuje sie mozliwości monitorowania transakcji w przypadku wielu escrow agents - depozytariuszy. Metoda ma na celu ochrone rynku przed atakami terrorystycznymi. (Schematy depozytowe (escrow) w mechanizmach kooperacyjnych przy wielu depozytariuszach)

Key Escrow Scheme with the Cooperation Mechanism of Multiple Escrow Agents

Cryptographic technology is always a highly sensitive dual-use technology. All nations have to face a dilemma in terms of password usage: on the one hand, to fully guarantee the safety and confidentiality of personal communication, as well as personal privacy and communication freedom required by law; on the other hand, to make sure law-enforcing departments and security organs crack down and prevent crime. It might be a great help for crime and terrorist organizations that the wide application of cryptography is made public. Many people believe that plain text communicated through the public network is accessible to an appropriate government agency if law permits. Therefore, it has become a continuous hot issue of cryptographic technology that how to design a cryptographic system through which legal persons are able to protect the safety of their information, yet being monitored by government in the range permitted by law. In this study, an in-depth study is carried out on the controversial key escrow technology, analyzing its composition and algorithm and pointing out possible attacks and preventive measures.

Key Escrow Attack Risk and Preventive Measures

In recent years, weather forecast plays an extremely important role in new energy power generation as well as prediction and early warning of major meteorological disasters. To improve the accuracy and stability of forecast, it gradually changes from a single deterministic forecast to a multi-mode integrated forecast, that is, the combination of several independent forecast results. CART algorithm divides the global data set into multiple data sets that are easy to model and establishes a local regression model on each local data set, which is especially suitable for modeling complex data with multiple characteristic variables. Therefore, this paper mainly studies the multi-mode integrated method based on CART and its application in the forecast of wind speed. The wind speed sampling data of the European Center for Medium-Range Weather Forecasts and National Centers for Environmental Prediction are integrated by using the integrated method based on CART and compared with single-mode forecast and BREM. The results of the simulation show that the CART has a significant improvement in the accuracy of forecast compared with BREM and the traditional single-mode forecast.

Multi-mode integrated method based on CART and its application in wind speed prediction

Due to the serious interference of illumination and background on the camera during the live operation of the distribution network robot, it is difficult to match, identify, and locate the feature points of the target image, such as the drainage line. This paper proposes the intelligent perception recognition and positioning method of the distribution network drainage line. First, YOLOv4 is used to identify and classify the typical parts of the distribution network and determine the two-dimensional position of the operation point. Subsequently, the Res-Unet segmentation network was improved to perform image segmentation of drainage lines and wires to avoid complex background interference. Finally, binocular vision is used to extract the center line of the wire through the image geometric moment and determine the image line of the wire and the center of the double eyes. The intersection line of the wire is the spatial three-dimensional coordinates of the wire. After the target detection, wire segmentation, and operation point positioning experiments, this method can achieve a positioning accuracy of 1 mm in the x and y directions and 3 mm in the z direction under the camera coordinate system, which provides a guarantee for accurate perception and recognition and reliable operation control of the power distribution robot operation.

Intelligent perception recognition and positioning method of distribution network drainage line

Under the background of carbon emission abatement worldwide, carbon trading is becoming an important carbon financing policy to promote emission mitigation. Aiming at the emerging couplings among various energy sectors, this paper investigates the low-carbon operation of the natural gas and electricity integrated energy systems (IES). Firstly, a bi-level optimal scheduling model is proposed, among which the carbon emission flow (CEF) model is employed to track the carbon flows accompanying power flows and identify the emission responsibility from the consumption-based perspective. At the same time, the locational marginal price (LMP) for electricity based on the optimal scheduling model is determined at the upper level. Then, at the lower level, a carbon-emission embedded demand side management (DSM) strategy is introduced, which can manage demands in response to electricity price and influence end-users to contribute to carbon reduction and economic benefits. The whole bi-level model is solved iteratively and reaches an equilibrium. Finally, case studies based on IEEE 39-bus system and Belgium 20-node illustrate the effectiveness of the proposed method in reducing carbon emissions and obtaining environmental profits.

Qiang Fan

Papers

Key Escrow Scheme with the Cooperation Mechanism of Multiple Escrow Agents

Key Escrow Attack Risk and Preventive Measures

Multi-mode integrated method based on CART and its application in wind speed prediction

Intelligent perception recognition and positioning method of distribution network drainage line

Low-carbon Operation of Natural Gas and Electricity Integrated Energy Systems Considering Carbon Trading and Demand Response