The Experts below are selected from a list of 222 Experts worldwide ranked by ideXlab platform
Pierangela Samarati - One of the best experts on this subject based on the ideXlab platform.
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Privacy and Identity Management for Life - Selective Exchange of Confidential Data in the Outsourcing Scenario
Privacy and Identity Management for Life, 2011Co-Authors: Sabrina Capitani Di Vimercati, Sara Foresti, Stefano Paraboschi, Gerardo Pelosi, Pierangela SamaratiAbstract:The evolution of information and communication technologies (ICTs) has introduced new ways for sharing and disseminating user-generated content through remote storage, publishing, and disseminating services. From an enterprise oriented point of view, these services offer cost effective and reliable data storage features that any organisation can take advantage of without long setup delays and capital expenses. Also, from an end-user point of view, distributed and shared data storage services offer considerable advantages in terms of reliability and constant availability of data. While on one hand data sharing services encourage and enhance the collaboration among users, on the other hand they need to provide proper protection of data, possibly enforcing access restrictions defined by the data owner. In this chapter, we present an approach for allowing users to delegate to an external service the enforcement of the access control Policy on their resources, while at the same time not requiring complete trust in the external service. Our solution relies on the translation of the access control Policy into an equivalent Encryption Policy on resources, and on a hierarchical key structure that exploits the relationships between groups or users. In this way, we limit both the number of keys to be maintained and the amount of Encryption to be performed, while keeping a good flexibility with respect to Policy updates and revocations.
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Encryption based Policy enforcement for cloud storage
International Conference on Distributed Computing Systems Workshops, 2010Co-Authors: Sabrina Capitani Di Vimercati, Sara Foresti, Sushil Jajodia, Stefano Paraboschi, Gerardo Pelosi, Pierangela SamaratiAbstract:Nowadays, users are more and more exploiting external storage and connectivity for sharing and disseminating user-generated content. To this aim, they can benefit of the services offered by Internet companies, which however assume that the service provider is entitled to access the resources. To overcome this limitation, we present an approach that does not require complete trust in the external service w.r.t. both resource content and authorization management, while at the same time allowing users to delegate to the provider the enforcement of the access control Policy on their resources. Our solution relies on the translation of the access control Policy into an equivalent Encryption Policy on resources and on a hierarchical key structure that limits both the number of keys to be maintained and the amount of Encryption to be enforced.
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Encryption policies for regulating access to outsourced data
ACM Transactions on Database Systems, 2010Co-Authors: Sabrina Capitani Di Vimercati, Sara Foresti, Sushil Jajodia, Stefano Paraboschi, Pierangela SamaratiAbstract:Current access control models typically assume that resources are under the strict custody of a trusted party which monitors each access request to verify if it is compliant with the specified access control Policy. There are many scenarios where this approach is becoming no longer adequate. Many clear trends in Web technology are creating a need for owners of sensitive information to manage access to it by legitimate users using the services of honest but curious third parties, that is, parties trusted with providing the required service but not authorized to read the actual data content. In this scenario, the data owner encrypts the data before outsourcing and stores them at the server. Only the data owner and users with knowledge of the key will be able to decrypt the data. Possible access authorizations are to be enforced by the owner. In this article, we address the problem of enforcing selective access on outsourced data without need of involving the owner in the access control process. The solution puts forward a novel approach that combines cryptography with authorizations, thus enforcing access control via selective Encryption. The article presents a formal model for access control management and illustrates how an authorization Policy can be translated into an equivalent Encryption Policy while minimizing the amount of keys and cryptographic tokens to be managed. The article also introduces a two-layer Encryption approach that allows the data owner to outsource, besides the data, the complete management of the authorization Policy itself, thus providing efficiency and scalability in dealing with Policy updates. We also discuss experimental results showing that our approach is able to efficiently manage complex scenarios.
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ICDCS Workshops - Encryption-Based Policy Enforcement for Cloud Storage
2010 IEEE 30th International Conference on Distributed Computing Systems Workshops, 2010Co-Authors: Sabrina Capitani Di Vimercati, Sara Foresti, Sushil Jajodia, Stefano Paraboschi, Gerardo Pelosi, Pierangela SamaratiAbstract:Nowadays, users are more and more exploiting external storage and connectivity for sharing and disseminating user-generated content. To this aim, they can benefit of the services offered by Internet companies, which however assume that the service provider is entitled to access the resources. To overcome this limitation, we present an approach that does not require complete trust in the external service w.r.t. both resource content and authorization management, while at the same time allowing users to delegate to the provider the enforcement of the access control Policy on their resources. Our solution relies on the translation of the access control Policy into an equivalent Encryption Policy on resources and on a hierarchical key structure that limits both the number of keys to be maintained and the amount of Encryption to be enforced.
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Managing key hierarchies for access control enforcement: Heuristic approaches
Computers & Security, 2010Co-Authors: Carlo Blundo, Sabrina Capitani Di Vimercati, Sara Foresti, Stefano Paraboschi, Stelvio Cimato, Alfredo De Santis, Pierangela SamaratiAbstract:Data outsourcing is emerging today as a successful paradigm allowing individuals and organizations to resort to external servers for storing their data, and sharing them with others. The main problem of this trend is that sensitive data are stored on a site that is not under the data owner's direct control. This scenario poses a major security problem since often the external server is relied upon for ensuring high availability of the data, but it is not authorized to read them. Data need therefore to be encrypted. In such a context, the application of an access control Policy requires different data to be encrypted with different keys so to allow the external server to directly enforce access control and support selective dissemination and access. The problem therefore emerges of designing solutions for the efficient management of an Encryption Policy enforcing access control, with the goal of minimizing the number of keys to be maintained by the system and distributed to users. In this paper, we prove that the problem of minimizing the number of keys is NP-hard and present alternative approaches for its solution. We first formulate the minimization problem as an instance of an integer linear programming problem and then propose three different families of heuristics, which are based on a key derivation tree exploiting the relationships among user groups. Finally, we experimentally evaluate the performance of our heuristics, comparing them with previous approaches.
Sabrina Capitani Di Vimercati - One of the best experts on this subject based on the ideXlab platform.
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Privacy and Identity Management for Life - Selective Exchange of Confidential Data in the Outsourcing Scenario
Privacy and Identity Management for Life, 2011Co-Authors: Sabrina Capitani Di Vimercati, Sara Foresti, Stefano Paraboschi, Gerardo Pelosi, Pierangela SamaratiAbstract:The evolution of information and communication technologies (ICTs) has introduced new ways for sharing and disseminating user-generated content through remote storage, publishing, and disseminating services. From an enterprise oriented point of view, these services offer cost effective and reliable data storage features that any organisation can take advantage of without long setup delays and capital expenses. Also, from an end-user point of view, distributed and shared data storage services offer considerable advantages in terms of reliability and constant availability of data. While on one hand data sharing services encourage and enhance the collaboration among users, on the other hand they need to provide proper protection of data, possibly enforcing access restrictions defined by the data owner. In this chapter, we present an approach for allowing users to delegate to an external service the enforcement of the access control Policy on their resources, while at the same time not requiring complete trust in the external service. Our solution relies on the translation of the access control Policy into an equivalent Encryption Policy on resources, and on a hierarchical key structure that exploits the relationships between groups or users. In this way, we limit both the number of keys to be maintained and the amount of Encryption to be performed, while keeping a good flexibility with respect to Policy updates and revocations.
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Encryption based Policy enforcement for cloud storage
International Conference on Distributed Computing Systems Workshops, 2010Co-Authors: Sabrina Capitani Di Vimercati, Sara Foresti, Sushil Jajodia, Stefano Paraboschi, Gerardo Pelosi, Pierangela SamaratiAbstract:Nowadays, users are more and more exploiting external storage and connectivity for sharing and disseminating user-generated content. To this aim, they can benefit of the services offered by Internet companies, which however assume that the service provider is entitled to access the resources. To overcome this limitation, we present an approach that does not require complete trust in the external service w.r.t. both resource content and authorization management, while at the same time allowing users to delegate to the provider the enforcement of the access control Policy on their resources. Our solution relies on the translation of the access control Policy into an equivalent Encryption Policy on resources and on a hierarchical key structure that limits both the number of keys to be maintained and the amount of Encryption to be enforced.
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Encryption policies for regulating access to outsourced data
ACM Transactions on Database Systems, 2010Co-Authors: Sabrina Capitani Di Vimercati, Sara Foresti, Sushil Jajodia, Stefano Paraboschi, Pierangela SamaratiAbstract:Current access control models typically assume that resources are under the strict custody of a trusted party which monitors each access request to verify if it is compliant with the specified access control Policy. There are many scenarios where this approach is becoming no longer adequate. Many clear trends in Web technology are creating a need for owners of sensitive information to manage access to it by legitimate users using the services of honest but curious third parties, that is, parties trusted with providing the required service but not authorized to read the actual data content. In this scenario, the data owner encrypts the data before outsourcing and stores them at the server. Only the data owner and users with knowledge of the key will be able to decrypt the data. Possible access authorizations are to be enforced by the owner. In this article, we address the problem of enforcing selective access on outsourced data without need of involving the owner in the access control process. The solution puts forward a novel approach that combines cryptography with authorizations, thus enforcing access control via selective Encryption. The article presents a formal model for access control management and illustrates how an authorization Policy can be translated into an equivalent Encryption Policy while minimizing the amount of keys and cryptographic tokens to be managed. The article also introduces a two-layer Encryption approach that allows the data owner to outsource, besides the data, the complete management of the authorization Policy itself, thus providing efficiency and scalability in dealing with Policy updates. We also discuss experimental results showing that our approach is able to efficiently manage complex scenarios.
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ICDCS Workshops - Encryption-Based Policy Enforcement for Cloud Storage
2010 IEEE 30th International Conference on Distributed Computing Systems Workshops, 2010Co-Authors: Sabrina Capitani Di Vimercati, Sara Foresti, Sushil Jajodia, Stefano Paraboschi, Gerardo Pelosi, Pierangela SamaratiAbstract:Nowadays, users are more and more exploiting external storage and connectivity for sharing and disseminating user-generated content. To this aim, they can benefit of the services offered by Internet companies, which however assume that the service provider is entitled to access the resources. To overcome this limitation, we present an approach that does not require complete trust in the external service w.r.t. both resource content and authorization management, while at the same time allowing users to delegate to the provider the enforcement of the access control Policy on their resources. Our solution relies on the translation of the access control Policy into an equivalent Encryption Policy on resources and on a hierarchical key structure that limits both the number of keys to be maintained and the amount of Encryption to be enforced.
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Managing key hierarchies for access control enforcement: Heuristic approaches
Computers & Security, 2010Co-Authors: Carlo Blundo, Sabrina Capitani Di Vimercati, Sara Foresti, Stefano Paraboschi, Stelvio Cimato, Alfredo De Santis, Pierangela SamaratiAbstract:Data outsourcing is emerging today as a successful paradigm allowing individuals and organizations to resort to external servers for storing their data, and sharing them with others. The main problem of this trend is that sensitive data are stored on a site that is not under the data owner's direct control. This scenario poses a major security problem since often the external server is relied upon for ensuring high availability of the data, but it is not authorized to read them. Data need therefore to be encrypted. In such a context, the application of an access control Policy requires different data to be encrypted with different keys so to allow the external server to directly enforce access control and support selective dissemination and access. The problem therefore emerges of designing solutions for the efficient management of an Encryption Policy enforcing access control, with the goal of minimizing the number of keys to be maintained by the system and distributed to users. In this paper, we prove that the problem of minimizing the number of keys is NP-hard and present alternative approaches for its solution. We first formulate the minimization problem as an instance of an integer linear programming problem and then propose three different families of heuristics, which are based on a key derivation tree exploiting the relationships among user groups. Finally, we experimentally evaluate the performance of our heuristics, comparing them with previous approaches.
Sara Foresti - One of the best experts on this subject based on the ideXlab platform.
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Privacy and Identity Management for Life - Selective Exchange of Confidential Data in the Outsourcing Scenario
Privacy and Identity Management for Life, 2011Co-Authors: Sabrina Capitani Di Vimercati, Sara Foresti, Stefano Paraboschi, Gerardo Pelosi, Pierangela SamaratiAbstract:The evolution of information and communication technologies (ICTs) has introduced new ways for sharing and disseminating user-generated content through remote storage, publishing, and disseminating services. From an enterprise oriented point of view, these services offer cost effective and reliable data storage features that any organisation can take advantage of without long setup delays and capital expenses. Also, from an end-user point of view, distributed and shared data storage services offer considerable advantages in terms of reliability and constant availability of data. While on one hand data sharing services encourage and enhance the collaboration among users, on the other hand they need to provide proper protection of data, possibly enforcing access restrictions defined by the data owner. In this chapter, we present an approach for allowing users to delegate to an external service the enforcement of the access control Policy on their resources, while at the same time not requiring complete trust in the external service. Our solution relies on the translation of the access control Policy into an equivalent Encryption Policy on resources, and on a hierarchical key structure that exploits the relationships between groups or users. In this way, we limit both the number of keys to be maintained and the amount of Encryption to be performed, while keeping a good flexibility with respect to Policy updates and revocations.
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Encryption based Policy enforcement for cloud storage
International Conference on Distributed Computing Systems Workshops, 2010Co-Authors: Sabrina Capitani Di Vimercati, Sara Foresti, Sushil Jajodia, Stefano Paraboschi, Gerardo Pelosi, Pierangela SamaratiAbstract:Nowadays, users are more and more exploiting external storage and connectivity for sharing and disseminating user-generated content. To this aim, they can benefit of the services offered by Internet companies, which however assume that the service provider is entitled to access the resources. To overcome this limitation, we present an approach that does not require complete trust in the external service w.r.t. both resource content and authorization management, while at the same time allowing users to delegate to the provider the enforcement of the access control Policy on their resources. Our solution relies on the translation of the access control Policy into an equivalent Encryption Policy on resources and on a hierarchical key structure that limits both the number of keys to be maintained and the amount of Encryption to be enforced.
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Encryption policies for regulating access to outsourced data
ACM Transactions on Database Systems, 2010Co-Authors: Sabrina Capitani Di Vimercati, Sara Foresti, Sushil Jajodia, Stefano Paraboschi, Pierangela SamaratiAbstract:Current access control models typically assume that resources are under the strict custody of a trusted party which monitors each access request to verify if it is compliant with the specified access control Policy. There are many scenarios where this approach is becoming no longer adequate. Many clear trends in Web technology are creating a need for owners of sensitive information to manage access to it by legitimate users using the services of honest but curious third parties, that is, parties trusted with providing the required service but not authorized to read the actual data content. In this scenario, the data owner encrypts the data before outsourcing and stores them at the server. Only the data owner and users with knowledge of the key will be able to decrypt the data. Possible access authorizations are to be enforced by the owner. In this article, we address the problem of enforcing selective access on outsourced data without need of involving the owner in the access control process. The solution puts forward a novel approach that combines cryptography with authorizations, thus enforcing access control via selective Encryption. The article presents a formal model for access control management and illustrates how an authorization Policy can be translated into an equivalent Encryption Policy while minimizing the amount of keys and cryptographic tokens to be managed. The article also introduces a two-layer Encryption approach that allows the data owner to outsource, besides the data, the complete management of the authorization Policy itself, thus providing efficiency and scalability in dealing with Policy updates. We also discuss experimental results showing that our approach is able to efficiently manage complex scenarios.
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ICDCS Workshops - Encryption-Based Policy Enforcement for Cloud Storage
2010 IEEE 30th International Conference on Distributed Computing Systems Workshops, 2010Co-Authors: Sabrina Capitani Di Vimercati, Sara Foresti, Sushil Jajodia, Stefano Paraboschi, Gerardo Pelosi, Pierangela SamaratiAbstract:Nowadays, users are more and more exploiting external storage and connectivity for sharing and disseminating user-generated content. To this aim, they can benefit of the services offered by Internet companies, which however assume that the service provider is entitled to access the resources. To overcome this limitation, we present an approach that does not require complete trust in the external service w.r.t. both resource content and authorization management, while at the same time allowing users to delegate to the provider the enforcement of the access control Policy on their resources. Our solution relies on the translation of the access control Policy into an equivalent Encryption Policy on resources and on a hierarchical key structure that limits both the number of keys to be maintained and the amount of Encryption to be enforced.
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Managing key hierarchies for access control enforcement: Heuristic approaches
Computers & Security, 2010Co-Authors: Carlo Blundo, Sabrina Capitani Di Vimercati, Sara Foresti, Stefano Paraboschi, Stelvio Cimato, Alfredo De Santis, Pierangela SamaratiAbstract:Data outsourcing is emerging today as a successful paradigm allowing individuals and organizations to resort to external servers for storing their data, and sharing them with others. The main problem of this trend is that sensitive data are stored on a site that is not under the data owner's direct control. This scenario poses a major security problem since often the external server is relied upon for ensuring high availability of the data, but it is not authorized to read them. Data need therefore to be encrypted. In such a context, the application of an access control Policy requires different data to be encrypted with different keys so to allow the external server to directly enforce access control and support selective dissemination and access. The problem therefore emerges of designing solutions for the efficient management of an Encryption Policy enforcing access control, with the goal of minimizing the number of keys to be maintained by the system and distributed to users. In this paper, we prove that the problem of minimizing the number of keys is NP-hard and present alternative approaches for its solution. We first formulate the minimization problem as an instance of an integer linear programming problem and then propose three different families of heuristics, which are based on a key derivation tree exploiting the relationships among user groups. Finally, we experimentally evaluate the performance of our heuristics, comparing them with previous approaches.
Stefano Paraboschi - One of the best experts on this subject based on the ideXlab platform.
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Privacy and Identity Management for Life - Selective Exchange of Confidential Data in the Outsourcing Scenario
Privacy and Identity Management for Life, 2011Co-Authors: Sabrina Capitani Di Vimercati, Sara Foresti, Stefano Paraboschi, Gerardo Pelosi, Pierangela SamaratiAbstract:The evolution of information and communication technologies (ICTs) has introduced new ways for sharing and disseminating user-generated content through remote storage, publishing, and disseminating services. From an enterprise oriented point of view, these services offer cost effective and reliable data storage features that any organisation can take advantage of without long setup delays and capital expenses. Also, from an end-user point of view, distributed and shared data storage services offer considerable advantages in terms of reliability and constant availability of data. While on one hand data sharing services encourage and enhance the collaboration among users, on the other hand they need to provide proper protection of data, possibly enforcing access restrictions defined by the data owner. In this chapter, we present an approach for allowing users to delegate to an external service the enforcement of the access control Policy on their resources, while at the same time not requiring complete trust in the external service. Our solution relies on the translation of the access control Policy into an equivalent Encryption Policy on resources, and on a hierarchical key structure that exploits the relationships between groups or users. In this way, we limit both the number of keys to be maintained and the amount of Encryption to be performed, while keeping a good flexibility with respect to Policy updates and revocations.
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Encryption based Policy enforcement for cloud storage
International Conference on Distributed Computing Systems Workshops, 2010Co-Authors: Sabrina Capitani Di Vimercati, Sara Foresti, Sushil Jajodia, Stefano Paraboschi, Gerardo Pelosi, Pierangela SamaratiAbstract:Nowadays, users are more and more exploiting external storage and connectivity for sharing and disseminating user-generated content. To this aim, they can benefit of the services offered by Internet companies, which however assume that the service provider is entitled to access the resources. To overcome this limitation, we present an approach that does not require complete trust in the external service w.r.t. both resource content and authorization management, while at the same time allowing users to delegate to the provider the enforcement of the access control Policy on their resources. Our solution relies on the translation of the access control Policy into an equivalent Encryption Policy on resources and on a hierarchical key structure that limits both the number of keys to be maintained and the amount of Encryption to be enforced.
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Encryption policies for regulating access to outsourced data
ACM Transactions on Database Systems, 2010Co-Authors: Sabrina Capitani Di Vimercati, Sara Foresti, Sushil Jajodia, Stefano Paraboschi, Pierangela SamaratiAbstract:Current access control models typically assume that resources are under the strict custody of a trusted party which monitors each access request to verify if it is compliant with the specified access control Policy. There are many scenarios where this approach is becoming no longer adequate. Many clear trends in Web technology are creating a need for owners of sensitive information to manage access to it by legitimate users using the services of honest but curious third parties, that is, parties trusted with providing the required service but not authorized to read the actual data content. In this scenario, the data owner encrypts the data before outsourcing and stores them at the server. Only the data owner and users with knowledge of the key will be able to decrypt the data. Possible access authorizations are to be enforced by the owner. In this article, we address the problem of enforcing selective access on outsourced data without need of involving the owner in the access control process. The solution puts forward a novel approach that combines cryptography with authorizations, thus enforcing access control via selective Encryption. The article presents a formal model for access control management and illustrates how an authorization Policy can be translated into an equivalent Encryption Policy while minimizing the amount of keys and cryptographic tokens to be managed. The article also introduces a two-layer Encryption approach that allows the data owner to outsource, besides the data, the complete management of the authorization Policy itself, thus providing efficiency and scalability in dealing with Policy updates. We also discuss experimental results showing that our approach is able to efficiently manage complex scenarios.
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ICDCS Workshops - Encryption-Based Policy Enforcement for Cloud Storage
2010 IEEE 30th International Conference on Distributed Computing Systems Workshops, 2010Co-Authors: Sabrina Capitani Di Vimercati, Sara Foresti, Sushil Jajodia, Stefano Paraboschi, Gerardo Pelosi, Pierangela SamaratiAbstract:Nowadays, users are more and more exploiting external storage and connectivity for sharing and disseminating user-generated content. To this aim, they can benefit of the services offered by Internet companies, which however assume that the service provider is entitled to access the resources. To overcome this limitation, we present an approach that does not require complete trust in the external service w.r.t. both resource content and authorization management, while at the same time allowing users to delegate to the provider the enforcement of the access control Policy on their resources. Our solution relies on the translation of the access control Policy into an equivalent Encryption Policy on resources and on a hierarchical key structure that limits both the number of keys to be maintained and the amount of Encryption to be enforced.
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Managing key hierarchies for access control enforcement: Heuristic approaches
Computers & Security, 2010Co-Authors: Carlo Blundo, Sabrina Capitani Di Vimercati, Sara Foresti, Stefano Paraboschi, Stelvio Cimato, Alfredo De Santis, Pierangela SamaratiAbstract:Data outsourcing is emerging today as a successful paradigm allowing individuals and organizations to resort to external servers for storing their data, and sharing them with others. The main problem of this trend is that sensitive data are stored on a site that is not under the data owner's direct control. This scenario poses a major security problem since often the external server is relied upon for ensuring high availability of the data, but it is not authorized to read them. Data need therefore to be encrypted. In such a context, the application of an access control Policy requires different data to be encrypted with different keys so to allow the external server to directly enforce access control and support selective dissemination and access. The problem therefore emerges of designing solutions for the efficient management of an Encryption Policy enforcing access control, with the goal of minimizing the number of keys to be maintained by the system and distributed to users. In this paper, we prove that the problem of minimizing the number of keys is NP-hard and present alternative approaches for its solution. We first formulate the minimization problem as an instance of an integer linear programming problem and then propose three different families of heuristics, which are based on a key derivation tree exploiting the relationships among user groups. Finally, we experimentally evaluate the performance of our heuristics, comparing them with previous approaches.
Baolin Qiu - One of the best experts on this subject based on the ideXlab platform.
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Fast Mode Decision and Encryption Policy in H.264/AVC Frame-skipping Transcoding
Journal of Computers, 2014Co-Authors: Xiaohong Zhang, Baolin QiuAbstract:H.264/AVC adopts Rate-Distortion Optimization (RDO) techniques to search all the prediction modes supported by standard in turn, then determine the optimal encoding mode which has the minimum rate-distortion cost. Frame-skipping transcoding among heterogeneous networks is a way to lower bitrate transcoding, which can solve incompatibility issues of video stream transmission. Aiming to varied motion problem of the video sequences, this paper introduces a set of adaptive threshold for inter mode decision, which can make a more correct code judgment of motion characteristics for the macroblock, also can obtain more reliable video quality; Combing the mode information of the skipping frame which can not be recovered, a simple and practicable Encryption Policy is introduced here, which avoids the shortcomings of traditional Encryption algorithm complexity. Experimental results show that the encoding time of the new algorithm is almost the same with that of the referenced algorithm, the peak value SNR increases steadily, so novel scheme guarantees nice video quality; Encryption Policy achieves the desired Encryption effect and efficiency, and broadens the applications of the video security technology.
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fast mode decision and Encryption Policy in h 264 avc frame skipping transcoding
Journal of Computers, 2014Co-Authors: Xiaohong Zhang, Baolin QiuAbstract:H.264/AVC adopts Rate-Distortion Optimization (RDO) techniques to search all the prediction modes supported by standard in turn, then determine the optimal encoding mode which has the minimum rate-distortion cost. Frame-skipping transcoding among heterogeneous networks is a way to lower bitrate transcoding, which can solve incompatibility issues of video stream transmission. Aiming to varied motion problem of the video sequences, this paper introduces a set of adaptive threshold for inter mode decision, which can make a more correct code judgment of motion characteristics for the macroblock, also can obtain more reliable video quality; Combing the mode information of the skipping frame which can not be recovered, a simple and practicable Encryption Policy is introduced here, which avoids the shortcomings of traditional Encryption algorithm complexity. Experimental results show that the encoding time of the new algorithm is almost the same with that of the referenced algorithm, the peak value SNR increases steadily, so novel scheme guarantees nice video quality; Encryption Policy achieves the desired Encryption effect and efficiency, and broadens the applications of the video security technology.