|
|
System of anonymous data collection
Troják, David ; Malina, Lukáš (referee) ; Dzurenda, Petr (advisor)
This thesis deals with contemporary approaches that provide higher protection of privacy of users. It focuses mainly on a group signature. In the practical part of this thesis I designed and implemented PS that is enable to gather information with the help of signal of a mobile device. The application was designed in accordance with fundamental cryptographic requirements such as the authenticity and the integrity of transmitted data. The anonymity of users is guaranteed through an application layer (the group signature) as well as through a network layer (Tor).
|
|
|
Internet privacy protection
Malina, Lukáš ; Doležel, Radek (referee) ; Hajný, Jan (advisor)
Anonymous authentication is a mean of authorizing a user without leakage of user personal information. The technology of Anonymous Authentication Systems (AAS) provides privacy of the user and yet preserves the security of the system. This thesis presents the basic cryptographic primitives, which can provide anonymous authentication. Among these primitives there are usually some asymmetric cryptosystems, but an essential part of anonymous authentication is based on zero knowledge protocols, blind signature schemes, threshold group schemes, etc., that are presented in Chapter 1. Generally, Anonymous Authentication Systems have application as electronic coin, electronic cash, group signatures, anonymous access systems, electronic vote, etc., which are analyzed and presented in Chapters 2 and 3. In the practical section, the implementation (in the environment .NET in C#) of the AAS system is presented and described in Chapter 4, which is being developed at the FEEC BUT.
|
|
|
Secure and privacy-preserving data communication
Bernát, Michal ; Člupek, Vlastimil (referee) ; Malina, Lukáš (advisor)
This thesis discusses the possibility of ensuring the safety, integrity and authenticity of data communication with respect to user privacy. This thesis describes the fundamentals of smart grid networks with capabilities of existing forms of security to communications that have been chosen as a target for application deployment of group signatures to ensure the security, integrity and authenticity of data communications. It describes the concept of a zero-knowledge and cryptography primitives. Further, the basic principles are presented, the history of development, and various schemes are compared based on the construction and performance. The second part is given to the deployment and optimization of group signatures for computationally limited devices. Within the draft report were to be implemented in the Java language chosen scheme HLCCN, DP and BBS. They were then tested under various platforms which were measured and evaluated performance parameters of the schemes. The optimization of the work is focused on the times of signatures, which are critical to a smart grid system. Under the platforms are deployed pre-processed pairing optimization methods and other methods resulting from the deployment platform as JPBWrappera and native libraries to deliver more efficient times of sgnaiture. At the end of the thesis are evaluated achievements of optimization methods and the appropriateness of the deployment of smart grids.
|
|
|
Group signature based on Secure Multi-party Computation
Klasovitý, Kristián ; Dzurenda, Petr (referee) ; Ricci, Sara (advisor)
Práce se věnuje implementaci skupinového podpisu, který využívá společný výpočet dvou stran k vypočítání tajné hodnoty využité k podpisu. Díky tomu zůstává soukromý klíč člena skupiny skrytý před manažerem skupiny, a nemůže být manažerem zneužit. Podpisové schéma podporuje revokaci a otevírání podpisů manažerem. Také byl představen způsob slepého vydávání atributového pověření, kde je pověření skryto před vydavatelem. Obě schémata byla spuštěna na více zařízeních a byl změřen čas jejich vykonání. Schéma pro skupinové podpisy bylo využito pro vytvoření aplikace, pomocí které je možné podepisovat dokumenty jménem skupiny. Implementace je spuštěna na více zařízeních, která komunikují pomocí NFC.
|
|
|
Secure Two-Party Computation for weak Boneh-Boyen Signature
Sečkár, M. ; Ricci, S.
Secure two-party computation allows two entities to securely calculate a common result keeping their private inputs secret. By applying this to the weak Boneh-Boyen signature, a trusted third party is able to sign the user’s message (or a secret key) without knowing its content (or value). In this article, we present a C library that implements a two-party computation algorithm for generating a user’s secret key that can be used in a group signature scheme. The library provides a structured output ready to be serialized and sent over a network. We also show the computational benchmarks of the implemented algorithms. The computations on the sender’s side are relatively fast, which broadens the possibilities of deployment on constrained devices.
|
|
|
Secure and privacy-preserving data communication
Bernát, Michal ; Člupek, Vlastimil (referee) ; Malina, Lukáš (advisor)
This thesis discusses the possibility of ensuring the safety, integrity and authenticity of data communication with respect to user privacy. This thesis describes the fundamentals of smart grid networks with capabilities of existing forms of security to communications that have been chosen as a target for application deployment of group signatures to ensure the security, integrity and authenticity of data communications. It describes the concept of a zero-knowledge and cryptography primitives. Further, the basic principles are presented, the history of development, and various schemes are compared based on the construction and performance. The second part is given to the deployment and optimization of group signatures for computationally limited devices. Within the draft report were to be implemented in the Java language chosen scheme HLCCN, DP and BBS. They were then tested under various platforms which were measured and evaluated performance parameters of the schemes. The optimization of the work is focused on the times of signatures, which are critical to a smart grid system. Under the platforms are deployed pre-processed pairing optimization methods and other methods resulting from the deployment platform as JPBWrappera and native libraries to deliver more efficient times of sgnaiture. At the end of the thesis are evaluated achievements of optimization methods and the appropriateness of the deployment of smart grids.
|
|
|
System of anonymous data collection
Troják, David ; Malina, Lukáš (referee) ; Dzurenda, Petr (advisor)
This thesis deals with contemporary approaches that provide higher protection of privacy of users. It focuses mainly on a group signature. In the practical part of this thesis I designed and implemented PS that is enable to gather information with the help of signal of a mobile device. The application was designed in accordance with fundamental cryptographic requirements such as the authenticity and the integrity of transmitted data. The anonymity of users is guaranteed through an application layer (the group signature) as well as through a network layer (Tor).
|
|
|
Internet privacy protection
Malina, Lukáš ; Doležel, Radek (referee) ; Hajný, Jan (advisor)
Anonymous authentication is a mean of authorizing a user without leakage of user personal information. The technology of Anonymous Authentication Systems (AAS) provides privacy of the user and yet preserves the security of the system. This thesis presents the basic cryptographic primitives, which can provide anonymous authentication. Among these primitives there are usually some asymmetric cryptosystems, but an essential part of anonymous authentication is based on zero knowledge protocols, blind signature schemes, threshold group schemes, etc., that are presented in Chapter 1. Generally, Anonymous Authentication Systems have application as electronic coin, electronic cash, group signatures, anonymous access systems, electronic vote, etc., which are analyzed and presented in Chapters 2 and 3. In the practical section, the implementation (in the environment .NET in C#) of the AAS system is presented and described in Chapter 4, which is being developed at the FEEC BUT.
|
guest ::
