The Biba Model or Biba Integrity Model developed by Kenneth J. Biba in 1975, is a formal state transition system of computer security policy describing a set of access control rules designed to ensure data integrity . Data and subjects are grouped into ordered levels of integrity. The model is designed so that subjects may not corrupt data in a level ranked higher than the subject, or be corrupted by data from a lower level than the subject.
18-460: In general the model was developed to address integrity as the core principle, which is the direct inverse of the Bell–LaPadula model which focuses on confidentiality. In general, preservation of data integrity has three goals: This security model is directed toward data integrity (rather than confidentiality ) and is characterized by the phrase: "read up, write down". This is in contrast to
36-499: A Lieutenant, also protecting the integrity of the mission ("write down"). The Biba model defines a set of security rules, the first two of which are similar to the Bell–LaPadula model . These first two rules are the reverse of the Bell–LaPadula rules: Bell%E2%80%93LaPadula model The Bell–LaPadula model ( BLP ) is a state machine model used for enforcing access control in government and military applications. It
54-476: A high-sensitivity document to a lower-sensitivity document may happen in the Bell–LaPadula model via the concept of trusted subjects. Trusted Subjects are not restricted by the Star-property. Trusted Subjects must be shown to be trustworthy with regard to the security policy. The Bell–LaPadula security model is directed toward access control and is characterized by the phrase "write up, read down" (WURD). Compare
72-475: A pamphlet written by a lowly commoner). Another analogy to consider is that of the military chain of command . A General may write orders to a Colonel, who can issue these orders to a Major. In this fashion, the General's original orders are kept intact and the mission of the military is protected (thus, "read up" integrity). Conversely, a Private can never issue orders to his Sergeant, who may never issue orders to
90-425: A pamphlet written by a lowly commoner). Another analogy to consider is that of the military chain of command . A General may write orders to a Colonel, who can issue these orders to a Major. In this fashion, the General's original orders are kept intact and the mission of the military is protected (thus, "read up" integrity). Conversely, a Private can never issue orders to his Sergeant, who may never issue orders to
108-400: Is a formal state transition system of computer security policy describing a set of access control rules designed to ensure data integrity . Data and subjects are grouped into ordered levels of integrity. The model is designed so that subjects may not corrupt data in a level ranked higher than the subject, or be corrupted by data from a lower level than the subject. In general the model
126-406: Is built on the concept of a state machine with a set of allowable states in a computer system. The transition from one state to another state is defined by transition functions. A system state is defined to be "secure" if the only permitted access modes of subjects to objects are in accordance with a security policy . To determine whether a specific access mode is allowed, the clearance of a subject
144-446: Is characterized by the phrase "read down, write up". In the Biba model, users can only create content at or below their own integrity level (a monk may write a prayer book that can be read by commoners, but not one to be read by a high priest). Conversely, users can only view content at or above their own integrity level (a monk may read a book written by the high priest, but may not read
162-488: Is compared to the classification of the object (more precisely, to the combination of classification and set of compartments, making up the security level ) to determine if the subject is authorized for the specific access mode. The clearance/classification scheme is expressed in terms of a partial order. The model defines one discretionary access control (DAC) rule and two mandatory access control (MAC) rules with three security properties: The transfer of information from
180-684: The Biba model , the Clark–Wilson model , and the Chinese Wall model. With Bell–LaPadula, users can create content only at or above their own security level (i.e. secret researchers can create secret or top-secret files but may not create public files; no write-down). Conversely, users can view content only at or below their own security level (i.e. secret researchers can view public or secret files, but may not view top-secret files; no read-up). The Bell–LaPadula model explicitly defined its scope. It did not treat
198-485: The Bell-LaPadula model which is characterized by the phrase "read down, write up". In the Biba model, users can only create content at or below their own integrity level (a monk may write a prayer book that can be read by commoners, but not one to be read by a high priest). Conversely, users can only view content at or above their own integrity level (a monk may read a book written by the high priest, but may not read
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#1732901741735216-450: The following extensively: The Strong Star Property is an alternative to the *-Property, in which subjects may write to objects with only a matching security level. Thus, the write-up operation permitted in the usual *-Property is not present, only a write-to-same operation. The Strong Star Property is usually discussed in the context of multilevel database management systems and is motivated by integrity concerns. This Strong Star Property
234-468: The most sensitive (e.g., "Top Secret"), down to the least sensitive (e.g., "Unclassified" or "Public"). The Bell–LaPadula model is an example of a model where there is no clear distinction between protection and security . The Bell–LaPadula model focuses on data confidentiality and controlled access to classified information , in contrast to the Biba Integrity Model which describes rules for
252-538: The normal operation of the system. The "principle of weak tranquility" states that security levels may never change in such a way as to violate a defined security policy. Weak tranquility is desirable as it allows systems to observe the principle of least privilege . That is, processes start with a low clearance level regardless of their owners clearance, and progressively accumulate higher clearance levels as actions require it. Biba model The Biba Model or Biba Integrity Model developed by Kenneth J. Biba in 1975,
270-409: The protection of data integrity . In this formal model, the entities in an information system are divided into subjects and objects. The notion of a " secure state " is defined, and it is proven that each state transition preserves security by moving from secure state to secure state, thereby inductively proving that the system satisfies the security objectives of the model. The Bell–LaPadula model
288-463: Was anticipated in the Biba model where it was shown that strong integrity in combination with the Bell–LaPadula model resulted in reading and writing at a single level. The tranquility principle of the Bell–LaPadula model states that the classification of a subject or object does not change while it is being referenced. There are two forms to the tranquility principle: the "principle of strong tranquility" states that security levels do not change during
306-424: Was developed by David Elliott Bell , and Leonard J. LaPadula, subsequent to strong guidance from Roger R. Schell , to formalize the U.S. Department of Defense (DoD) multilevel security (MLS) policy. The model is a formal state transition model of computer security policy that describes a set of access control rules which use security labels on objects and clearances for subjects. Security labels range from
324-416: Was developed to address integrity as the core principle, which is the direct inverse of the Bell–LaPadula model which focuses on confidentiality. In general, preservation of data integrity has three goals: This security model is directed toward data integrity (rather than confidentiality ) and is characterized by the phrase: "read up, write down". This is in contrast to the Bell-LaPadula model which
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