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Questions tagged [access-control]

11 questions
7
votes
2 answers

Fine-grained security models for XML data

Access control models are typically very coarse-grained, allowing one access to a resource (possibly with some combination of read/write/execute permission) or exclude such access. Some models of database security allow access to be granted on a per…
Dave Clarke
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6
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2 answers

Why is there readonly (const) in C++, but not writeonly (sink)?

C++ initially had "readonly" and "writeonly" qualifiers, before "readonly" was renamed to "const", and "writeonly" removed. My question is: What are the problems with "writeonly" (or a "sink" qualifier)? There are (non-object oriented) programming…
Thomas Klimpel
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5
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4 answers

Direct vs. Random Access

Would someone please clarify for me the difference between direct and random access? Specifically, why does this Wikipedia article on Direct Access Storage Devices distinguish between the two: The direct access capability, occasionally and…
malhobayyeb
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3
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2 answers

Can the Bell-LaPadula model emulate the Chinese Wall model?

I have been reading on security policies and the question wether Bell-LaPadula can be used to implement Chinese Wall. Does anyone know more about it?
siddharth
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2
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1 answer

Formally modelling and describing access rights

Is there a formal theory or framework described in text books that models access rights in a mathematical way. I would expect things similar to the following: We have data (objects). We have operations on these objects (CRUD, create, read, update…
Harald
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2
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1 answer

Access control matrices: who are the subjects: users or processes?

I'm studying the basics of security in computers. The doubt I have is that the access control matrix is presented as a matrix whose rows are the subjects and the columns are the objects. Also subjects are defined both in Windows and Unix (and…
Gonzalo_Arcos
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3 answers

Is it possible to define branches which, once taken once, will become the default forever?

Assuming I have a very simple branching: switch on var: 1 => branch1 2 => branch2 default => branch3 And I wish to implement a program that will forever take "branch2" when entering this sequence of instructions once branch2 is taken. This…
George
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What is an access control graph?

A question I came across describes a scenario of an information system in a clerical office and states- "Identify the sets of S={subjects}, O={objects} and P={privileges} for the above systems of the manufacturing organisation, and model the case…
Amy Cohen
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1 answer

Where can I find good study material on Role Mining?

I need to cover these topics in Role Mining. If anyone knows good site which well summarizes the topics and concepts are well explained please help out. Basic role mining problem • Delta-approx RMP • Min-noise RMP • Nature of the RMP problems •…
siddharth
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0
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0 answers

why vulnerable time in pure aloha is not tp

I understand that vulnerable time in CSMA cd is Tp (Propagation time). This is because collision can occur in Tp duration since one bit has to travel to the end. My question is- Why that is not true in the case of Aloha ?. Why we do not have the…
user3699192
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Difference between data flow and control flow

I am trying to read a paper. I can’t understand the difference between data flow and control. Maybe control flow means OS's or hardware's steps taken for execution of statements whereas data flow stands for passage of data as a result of execution…
user2994783
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