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War of Control Hijacking
Published in Uzzal Sharma, Parmanand Astya, Anupam Baliyan, Salah-ddine Krit, Vishal Jain, Mohammad Zubair Khan, Advancing Computational Intelligence Techniques for Security Systems Design, 2023
Ragini Karwayun, Monika Sainger
The integer overflow occurs when an arithmetic operation tries to generate a numeric value that is larger than the storage space allocated to store that value. It has been a very common problem for a very long time, but now integer overflow vulnerabilities are used by hackers. There is a race between the number of integer overflow vulnerabilities exploited and the detection methods used for integer overflows, both growing at a very rapid pace.
The all configuration mean energy multiconfiguration self-consistent-field method. I. Equal configuration weights
Published in Molecular Physics, 2019
The total effort to compute the ACME using this recursive algorithm is independent of NCSF. This step replaces the eigenpair solutions within each iteration of a conventional MCSCF optimisation, which is the dominant computational effort for larger values of nact. The individual Hkk elements are not computed with this approach, only the summation Tr(H) is available, and of course the individual Ek state energies are also unavailable. The algorithm is summarised in Figure 3 for one possible choice for the DO loop ranges and the associated recursions; the algorithm may also be adapted to loop over orbitals in decreasing order, or in mixed directions, e.g. q increasing and p decreasing. Our implementation of this algorithm also accounts for point group symmetry. All of the quantities, xk, , and the 11a and 11b1 propagations, carry irrep labels, and the initiation, propagation, and termination steps all account for the lower-walk, arc, and upper-walk irreps. The irrep labels are combined for each arc djk according to where λj is the irrep of the lower-walk from the graph tail to the lower node j of the arc, λjk is the irrep of the arc, is the irrep of the upper-walk from the upper node k of the arc to the graph head, and λstate is the irrep of interest in the state averaging. This irrep labelling increases the indexing overhead by a factor of the order of the point group, but it allows the state averaging to be limited not only to CSFs with the target spin multiplicity, but also to a single target point-group irrep or to a state average over several target irreps. In the special case that CSFs of all irreps are averaged with equal weights, point group symmetry can be ignored in the algorithm. Because this algorithm is intended for very large CSF expansions, the xk and computation is performed with floating point arithmetic rather than integer arithmetic, thereby eliminating any concern with integer overflow within the algorithm for large Shavitt graphs.