type of access control by which the operating system constrains the ability of a subject or initiator to access or generally perform some sort of operation on an object or target. In practice, a subject is usually a process or thread; objects are constructs such as files, directories, TCP/UDP ports, shared memory segments, IO devices etc. Subjects and objects each have a set of security attributes. Whenever a subject attempts to access an object, an authorization rule enforced by the operating system kernel examines these security attributes and decides whether the access can take place. Any operation by any subject on any object will be tested against the set of authorization rules (aka policy) to determine if the operation is allowed. A database management system, in its access control mechanism, can also apply mandatory access control; in this case, the objects are tables, views, procedures, etc. With mandatory access control, this security policy is centrally controlled by a security policy administrator; users do not have the ability to override the policy and, for example, grant access to files that would otherwise be restricted.
By contrast, discretionary access control (DAC), which also governs the ability of subjects to access objects, allows users the ability to make policy decisions and/or assign security attributes. (The traditional UNIX system of users, groups, and read-write-execute permissions is an example of DAC.) MAC-enabled systems allow policy administrators to implement organization-wide security policies. Unlike with DAC, users cannot override or modify this policy, either accidentally or intentionally. This allows security administrators to define a central policy that is guaranteed (in principle) to be enforced for all users. Historically and traditionally, MAC has been closely associated with multi-level secure (MLS) systems.
The Trusted Computer System Evaluation Criteria (TCSEC), the seminal work on the subject, defines MAC as “a means of restricting access to objects based on the sensitivity (as represented by a label) of the information contained in the objects and the formal authorization (i.e., clearance) of subjects to access information of such sensitivity”. Early implementations of MAC such as Honeywell’s SCOMP, USAF SACDIN, NSA Blacker, and Boeing’s MLS LAN focused on MLS to protect military-oriented security classification levels with robust enforcement. Originally, the term MAC denoted that the access controls were not only guaranteed in principle, but in fact. Early security strategies enabled enforcement guarantees that were dependable in the face of national lab level attacks.
Data classification awareness:
For any IT initiative to succeed, particularly a security-centric one such as data classification, it needs to be understood and adopted by management and the employees using the system. Changing a staff’s data handling activities, particularly regarding sensitive data, will probably entail a change of culture across the organization. This type of movement requires sponsorship by senior management and its endorsement of the need to change current practices and ensure the necessary cooperation and accountability. The safest approach to this type of project is to begin with a pilot. Introducing substantial procedural changes all at once invariably creates frustration and confusion. I would pick one domain, such as HR or R&D, and conduct an information audit, incorporating interviews with the domain’s users about their business and regulatory requirements. The research will give you insight into whether the data is business or personal, and whether it is business-critical.
This type of dialogue can fill in gaps in understanding between users and system designers, as well as ensure business and regulatory requirements are mapped appropriately to classification and storage requirements. Issues of quality and data duplication should also be covered during your audit. Categorizing and storing everything may seem an obvious approach, but data centers have notoriously high maintenance costs, and there are other hidden expenses; backup processes, archive retrieval and searches of unstructured and duplicated data all take longer to carry out, for example. Furthermore, too great a degree of granularity in classification levels can quickly become too complex and expensive.
There are several dimensions by which data can be valued, including financial or business, regulatory, legal and privacy. A useful exercise to help determine the value of data, and to which risks it is vulnerable, is to create a data flow diagram. The diagram shows how data flows through your organization and beyond so you can see how it is created, amended, stored, accessed and used. Don’t, however, just classify data based on the application that creates it, such as CRM or Accounts.
This type of distinction may avoid many of the complexities of data classification, but it is too blunt an approach to achieve suitable levels of security and access. One consequence of data classification is the need for a tiered storage architecture, which will provide different levels of security within each type of storage, such as primary, backup, disaster recovery and archive — increasingly confidential and valuable data protected by increasingly robust security. The tiered architecture also reduces costs, with access to current data kept quick and efficient, and archived or compliance data moved to cheaper offline storage.
Organizations need to protect their information assets and must decide the level of risk they are willing to accept when determining the cost of security controls. According to the National Institute of Standards and Technology (NIST), “Security should be appropriate and proportionate to the value of and degree of reliance on the computer system and to the severity, probability and extent of potential harm.
Requirements for security will vary depending on the particular organization and computer system.”1 To provide a common body of knowledge and define terms for information security professionals, the International Information Systems Security Certification Consortium (ISC2) created 10 security domains. The following domains provide the foundation for security practices and principles in all industries, not just healthcare: Security management practices
Access control systems and methodology
Telecommunications and networking security
Security architecture and models
Application and systems development security
Business continuity and disaster recovery planning
Laws, investigation, and ethics
In order to maintain information confidentiality, integrity, and availability, it is important to control access to information. Access controls prevent unauthorized users from retrieving, using, or altering information. They are determined by an organization’s risks, threats, and vulnerabilities. Appropriate access controls are categorized in three ways: preventive, detective, or corrective. Preventive controls try to stop harmful events from occurring, while detective controls identify if a harmful event has occurred. Corrective controls are used after a harmful event to restore the system. Risk mitigation
Assume/Accept: Acknowledge the existence of a particular risk, and make a deliberate decision to accept it without engaging in special efforts to control it. Approval of project or program leaders is required. Avoid: Adjust program requirements or constraints to eliminate or reduce the risk. This adjustment could be accommodated by a change in funding, schedule, or technical requirements. Control: Implement actions to minimize the impact or likelihood of the risk. Transfer: Reassign organizational accountability, responsibility, and authority to another stakeholder willing to accept the risk Watch/Monitor: Monitor the environment for changes that affect the nature and/or the impact of the risk
Access control policy framework consisting of best practices for policies, standards, procedures, Guidelines to mitigate unauthorized access :
IT application or program controls are fully automated (i.e., performed automatically by the systems) designed to ensure the complete and accurate processing of data, from input through output. These controls vary based on the business purpose of the specific application. These controls may also help ensure the privacy and security of data transmitted between applications. Categories of IT application controls may include:
Completeness checks – controls that ensure all records were processed from initiation to completion. Validity checks – controls that ensure only valid data is input or processed. Identification – controls that ensure all users are uniquely and irrefutably identified. Authentication – controls that provide an authentication mechanism in the application system. Authorization – controls that ensure only approved business users have access to the application system. Input controls – controls that ensure data integrity fed from upstream sources into the application system. Forensic controls – control that ensure data is scientifically correct and mathematically correct based on inputs and outputs Specific application (transaction processing) control procedures that directly mitigate identified financial reporting risks.
There are typically a few such controls within major applications in each financial process, such as accounts payable, payroll, general ledger, etc. The focus is on “key” controls (those that specifically address risks), not on the entire application. IT general controls that support the assertions that programs function as intended and that key financial reports are reliable, primarily change control and security controls; IT operations controls, which ensure that problems with processing are identified and corrected.
Specific activities that may occur to support the assessment of the key controls above include: Understanding the organization’s internal control program and its financial reporting processes. Identifying the IT systems involved in the initiation, authorization, processing, summarization and reporting of financial data; Identifying the key controls that address specific financial risks; Designing and implementing controls designed to mitigate the identified risks and monitoring them for continued effectiveness; Documenting and testing IT controls;
Ensuring that IT controls are updated and changed, as necessary, to correspond with changes in internal control or financial reporting processes; and Monitoring IT controls for effective operation over time.
http://hokiepokie.org/docs/acl22003/security-policy.pdf Coe, Martin J. “Trust services: a better way to evaluate I.T. controls:
fulfilling the requirements of section 404.” Journal of Accountancy 199.3 (2005): 69(7). Chan, Sally, and Stan Lepeak. “IT and Sarbanes-Oxley.” CMA Management 78.4 (2004): 33(4). P. A. Loscocco, S. D. Smalley, P. A. Muckelbauer, R. C. Taylor, S. J. Turner, and J. F. Farrell. The Inevitability of Failure: The Flawed Assumption of Security in Modern Computing Environments. In Proceedings of the 21st National Information Systems Security Conference, pages 303–314, Oct. 1998.