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Abstract— Secure knowledge management refers to the management of knowledge while sharing among members of virtual communities in distributed computer networks adhering to the principles of security and privacy. Security of the knowledge management over the network is critical, since one cannot restrict the knowledge sharing geographically and moreover the intellectual asset has to be protected. This paper proposes a new architecture for managing knowledge over the public network securely. The architecture stack has different level of security. One can implement the architecture with any number of stack levels depending upon the amount of security constraints that would like to impose on knowledge. Moreover hierarchical access controls proposed in this paper has a number of visual modes to inherit the access permissions and policies of the different roles.

I. INTRODUCTION n today’s corporate world, as the organization grow larger and become truly global in outlook, the knowledge sharing through insecure network and it6s

management will also become advengerous. In the contemporary world, the security has entered into the knowledge economy; knowledge has become the most precious property of any business or academic institution and is a care element in an evolving cooperation.

In the contemporary world, the society has entered into the knowledge age, or the age of the knowledge economy, knowledge has become the most precious property of any business or academic institution and is a core element in an evolving cooperation. Knowledge is the most important core resources of any enterprise and will remain the origin through which enterprise maintains the lasting competitive advantage. According to the attribute of knowledge and the degree of gaining and transmitting knowledge, the enterprise knowledge is divided into explicit knowledge and tacit knowledge [15]. Tacit knowledge is concealed and also it is difficult to be imitated, it cannot be easily duplicated or stolen. So tacit knowledge is the foundation and the

fountain head of enterprise and it forms the care competitive ability. Tacit knowledge is more perfect than explicit knowledge and can create the value. The essence of enterprise core ability is tacit knowledge. Therefore highly effective management of the enterprise tacit knowledge is the key to obtaining the continuous competitive advantage, and it is the core link of realizing the transformation from tacit knowledge to explicit knowledge.

Knowledge management is about sharing the intellectual capital, resources and enterprise, to increase the overall performance of system and enterprise itself. The knowledge management practices have received momentum with the advent of information technology and sharing the data over network, using internet techniques. For a decade or so, enterprise within intranet promotes knowledge management, so that the employees can share enterprise and corporate information for the benefit of organization itself. Furthermore, when an expert leaves an enterprise, it is important to capture their knowledge and practices so that the corporation does not loose the valuable information acquired through many years of hard work [16]. Knowledge management has key role to play as they are more and more popular in modern information technology era.

Security in web data management, sharing multimedia systems and collaboration systems are also contribute towards securing knowledge management practices. Moreover one needs to protect the organizations important assents such as intellectual property and expertise along with trade secrets, which is to be kept highly confidential so that competitors do not have any access to it.

To share knowledge with in the twp departments of an organization, which are located in two different geographical locations, public network would be appropriate in terms of cost of transmission. The security system in the public network is exposed vulnerability. Managing the security over the public network during

Architecture for Secure Knowledge Management over the Network

Vinu V Das Department of Computer Science and Engineering,

SAINTGITS College of Engineering, Kerala - 686532, India. Email: prof.vinuvdas@gmail.com

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978-1-4244-2900-4/08/$25.00 ©2008 IEEE ICIAFS 08

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the knowledge management is real challenge and requires much attention.

To have a secure knowledge management, there must have a secure strategies, process and matrices. The knowledge administrator may specify to whom the knowledge can be transferred and up to what extent the access permissions may be given. The knowledge sharing and knowledge transfer operations must also enforce access control and security policies. Number of access controls such as Role-based Access Control, RABC, and Usage Control, UCON, are proposed to secure the knowledge management. Present architectures are specially designed to work efficiently with in the organization’s intranet not in the public network.

This paper proposes a new architecture stack with different security level of knowledge management over the public network.

Number of access control levels based on the nature of data file, user, role, IP, domain. One have the freedom to select and implement one or more of the access control stacks based on the security levels. Numbers of visual modes have also proposed in every access control to provide hierarchical structure for inheriting then between

roles.

II. PROPOSED ACCESS CONTROL STACK There are several aspects to secure knowledge

management. The proposed architecture restricts itself on confidentiality, trust and privacy management of access controls. Access control refers to control (or permission) to access/modify a information or knowledge in an network.

The proposed architecture has seven access control levels to ensure the confidentiality and security for knowledge management over the public network. For each control access have simple read-write-execute policies. The policies are identified with permission number as shown in Table 1.

The permission number corresponding to the file may be given to set or reset policies of any access controls. How far the file should be open to user in different group role and IP domain, is based on these access control, AC, policies. The proposed AC stack is shown in figure 1.

The relevant of highest and lowest privilege in grating the permission is that permission set in the highest privilege AC level has higher priority over the Ac level

having lowest privilege. For example, even though end user A has R+W+X permission over a directory, A may not be able write if the corresponding file that contains knowledge has no write (w) permission.

The ACs are arranged on by one in stack, where file based AC is in top having highest privilege rights and domain based AC is lowest privilege. The entire AC stack can be divided into three section depends upon granting the permission; more precisely the details required to take appropriate decision. A high-level

TABLE 1 – SIMPLE PERMISSION POLICIES

Permission Permission No: Read 1 Write 2 Execute 4 Read + Write 3 Read + Execute 5 Write + Execute 6 Read + Write + Execute 7

Fig 1 – Proposed access control stack

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permission section includes Domain Based Access Control, DBAC, and Internet Protocol Based Access Control, IPBAC, levels. This level in this section grants the access permissions based on the input network information (IP address) from the end user system details. Middle-level permission section has User Based Access Control, UBAC, Role Based Access Control, RBAC, and Group Based Access Control, GBAC, levels. The information to grand the permission must be attached along with header of each packet request for AC. These details may also be encrypted using any secure public key cryptographic algorithms to avoid any data modification. The low-level permission section include both file based Access Control, FBAC, and Directory Based Access Control, DBAC, levels, where the permission are set on the knowledge management server. Based on this permission a user may grand or deny permission on a specific knowledge file.

Knowledge (or data information) is stored in files, which is further stored in directories, having basic permission set. For example, end user A is sending request for retrieving knowledge via a public network.

Once the request is reached to the knowledge management server, the packet will go trough on the number of security checks. These secondary checks are regulated by the number of access control levels in the stack, from bottom to top. The specific permission (Read, Write or Execute) is granted only if the security clearance is obtained from all the seven AC levels to access knowledge in a file. This will enforce the intelligent property protection of the organization even during sharing through public network. The core of this architecture is the individual strength of each AC level and its secure knowledge –management strategies, which is discussed in this section. A. Domain Based Access Control (DBAC)

Domain is a subtree of the naming scheme used in the public network to manage the efficiently. Domain names are hierarchical in nature, with most significant part of the name on the right, and it consists of a sequence of alphanumeric segment separated by periods. The systems in a network are arranged as subtree under a domain name server systems, which may have one or more parental systems. The DBAC has lowest privilege rights in AC stack.

In DBAC, first level of filtering is done, whether a knowledge have any permission to access it, which is based on a request from a domain. If at all there is a permission how far a user can read or write or execute. This is achieved by setting the permissions for set of sub domains or systems in a domain B. IP Based Access Control (IPBAC)

Internet Protocol (IP) is to provide a addressing system in a seamless internetworking communication system. The IPBAC has slightly higher privilege than DBAC and places above it. In IPBAC, the request from the end user is filtered in the second time to grand or deny the permission to access a knowledge in the file. In a public network, using the permissions settings in IPBAC, knowledge can be managed based on the IP address of the end user.

The DBAC and IPBAC can be implemented in layer 3 higher of any network architecture. This high level permission can also be implemented in the network structure of the knowledge server. If a permission is not set on any IP, then its member domain’s permission will be inherited and vice versa. C. Role Based Access Control (RBAC)

Fig 2 – Policy inheritance in higher level.

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Different roles (or designations) have different decision managing and processing capacity when we think of sharing the knowledge. Such role based permissions and rights may be set for secure knowledge management. Two different users in same role can have different knowledge sharing permissions, as it is with IPs domains and user-groups. For example, end-user A and B is in same role sharing same role policies. But if their level of trustworthy is different, then it can be reflected in their individual user policies. If the permissions ad policies of a user ad his member role and group are same on a particular knowledge, only one (among user, role, or group) of the AC level permissions would be sufficient to enforce the control. Only for middle and higher levels ACs have policies and permissions; the low level ACs has only permissions. D. Group Based Access Control (GBAC)

Users having different roles can be in a same (project) group to share knowledge. A request to share knowledge is filtered by GBAC level only after the RBAC. Only the net result of RBAC and GBAC will be passes to UBAC, not the individual level permissions. For example, one request has only a read permission in RBAC but read+write in GBAC, and then only group permissions will be passed to UBAC. This will help one to share a common knowledge required to carry out a project. One group can also become a member of another group. E. User Based Access Control (UBAC)

Users are the basic members in a network, who would like to use or access or share knowledge. The basic read-write-execute permissions can be set for any specific user against the knowledge available in file. The request for accessing knowledge is granted only is the basic

permission allows. All users may have both roles and/or group, that is, all the users will have a role and may be a member of a group(s). Every user who likely to take part in knowledge sharing will have user account with permission and polices set. Based on these, decision is taken to grand or deny the permissions on a knowledge. F. Directory Based Access Control (DBAC)

Knowledge file (or data base) is stored further in a directory whose permissions can be set. Provisions is not required (or provided) to set the policies for the ACs in a low level ACs G. File Based Access Control (FBAC)

Highest privileged AC’s in the architecture stack is FBAC, whose knowledge is actually stored for sharing among different groups and/or users. In the highest and middle level blocks, the cumulative result is taken into consideration; but in low level AC’s individual access permissions are considered when a request is processed.

Highest privileged ACs in the architecture stack is FBAC, where knowledge is actually stored for sharing among different groups and/or users. In the highest and middle level bocks, the cumulative result is taken into consideration; but in low-level ACs individual access permission are considered when a request is processed.

III. PROPOSED POLICY INHERITANCE Policies are rules and regulations for validation,

allowing the service at any specific time, logging the activities etc. Both higher and middle block AC levels have policies, which can be set, inherited and override. In heritance is an optional feature when an IP-Domain and User-Role-Group membership is configured.

Fig 3 – Middle level policy inheritance

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Policies for any individual in higher-middle blocks can be configured in three visual modes: public, protected and private. The policies in the public mode can be inherited to both protected and private; and the protected policies can only be inherited to private mode based on the inheritance parameters. Policies in the private visual mode cannot be inherited.

When an IP becomes a member of a domain, by default, public policies will be inherited to all the IP members is that specific domain and vice-versa, into their own private mode policies. Public policies can also be inherited into protected mode and protected policies can be inherited into private policy manually. Figure 2 shows the method to inherit the permissions and policies in the higher level ACs.

Policies newly inherited to domain will be applied to all the member IPs middle level ACs has policies in three visual modes that can be inherited. Whenever a role (having only protected and public visual modes) is assigned to a user, the policies can also be inherited. The users can also be member of one or more group, so that groups inherit user’s policy. One group may also be in other group(s) to get new member group policy, so that user’s in that group inherit its policies. Figure 3 shows the typical policy inheritance in middle level ACs.

Role R is assigned to user D to get its few new policies inherited from R. This user D is a member of Group G1, to inherit all (including inherited policies) protected and public policies depends upon the options in the inheritance process. User A, B and C are the members of the group G1 and gets its policies. In this case group G2 has user X, Y and Z, they get the policies of G2, and G1, is also a member of the G2 to get the policies of G1.

IV. CONCLUSION This paper has discussed a architecture using number of access control stack, which is a solutions to some of the key issues in knowledge management over a public network. It further increased the security strength when it incorporates inheritance into access control stack. Trust management and negotiation for knowledge management can efficiently implement using policy and permission settings, regarding the sharing of knowledge between multiple organization or different departments within an organization, it is very important that the different parties establish trusted network rule for collaboration. The levels are structured in such a way to give maximum security; but strength of the access control stack is further enhanced by establishing efficiently and privacy oriented trusted network rules.

ACKNOWLEDGMENT I praise, and worship by giving thanks to my Lord and

Saviour Jesus Christ, without Whom nothing would have been possible for me.

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