55 research outputs found
Three Hash Functions Comparison on Digital Holy Quran Integrity Verification
This paper provides a study of hash functions comparison on holy Quran integrity verification to ensure integrity of data in digital copy of holy Quran. There are many methods available in data security area for integrity verification. This study presents a comparison of three cryptographic hash functions SHA256, RIPEMD160 and Blake3 which used to verify the integrity of digital holy Quran and determine which one is better. Blake3 hash function is chosen in this proposed schema because it has many characteristics, the most important of which is the speed characteristic, and it will be mentioned in detail in Background section. Furthermore security analysis and performance analysis are focused on this study. In security analysis by apply four experiments to find out the strength and effectiveness of each three hash functions and all possible possibilities of hash collisions be carefully analysed and studied. Speed in term of execution time is measuring for all three hash function and this is under the umbrella of the performance analysis. The results that we have obtained say that the Blake3 hash function is the fastest function with the rest two hash functions. And the resulting number of the time that the attacker need to come up with a fake verse using SHA256/BLAKE3 will be greater than the number obtained by using RIPEMD160.
 
Cognitive-behavioral and electrophysiological evidence of the affective consequences of ignoring stimulus representations in working memory
Ignoring visual stimuli in the external environment leads to decreased liking of those items, a phenomenon attributed to the affective consequences of attentional inhibition. Here we investigated the generality of this “distractor devaluation” phenomenon by asking whether ignoring stimuli represented internally within visual working memory has the same affective consequences. In two experiments we presented participants with two or three visual stimuli and then, after the stimuli were no longer visible, provided an attentional cue indicating which item in memory was the target they would have to later recall, and which were task-irrelevant distractors. Participants subsequently judged how much they liked these stimuli. Previously-ignored distractors were consistently rated less favorably than targets, replicating prior findings of distractor devaluation. To gain converging evidence, in Experiment 2, we also examined the electrophysiological processes associated with devaluation by measuring individual differences in attention (N2pc) and working memory (CDA) event-related potentials following the attention cue. Larger amplitude of an N2pc-like component was associated with greater devaluation, suggesting that individuals displaying more effective selection of memory targets—an act aided by distractor inhibition—displayed greater levels of distractor devaluation. Individuals showing a larger post-cue CDA amplitude (but not pre-cue CDA amplitude) also showed greater distractor devaluation, supporting prior evidence that visual working-memory resources have a functional role in effecting devaluation. Together, these findings demonstrate that ignoring working-memory representations has affective consequences, and adds to the growing evidence that the contribution of selective-attention mechanisms to a wide range of human thoughts and behaviors leads to devaluation
The costs of switching attentional sets
People prioritize those aspects of the visual environment that match their attentional set. In the present study, we investigated whether switching from one attentional set to another is associated with a cost. We asked observers to sequentially saccade toward two color-defined targets, one on the left side of the display, the other on the right, each among a set of heterogeneously colored distractors. The targets were of the same color (no attentional set switch required) or of different colors (switch of attentional sets necessary), with each color consistently tied to a side, to allow observers to maximally prepare for the switch. We found that saccades were less accurate and slower in the switch condition than in the no-switch condition. Furthermore, whenever one of the distractors had the color associated with the other attentional set, a substantial proportion of saccades did not end on the target, but on this distractor. A time course analysis revealed that this distractor preference turned into a target preference after about 250–300 ms, suggesting that this is the time required to switch attentional sets
Attending to what and where: Background connectivity integrates category-based and spatial attention
Top-down attention alters background connectivity between retinotopic and category-specific visual areas
Cognitive-behavioral and electrophysiological evidence of the affective consequences of ignoring stimulus representations in working memory
Ignoring visual stimuli in the external environment leads to decreased liking of those items, a phenomenon attributed to the affective consequences of attentional inhibition. Here we investigated the generality of this “distractor devaluation” phenomenon by asking whether ignoring stimuli represented internally within visual working memory has the same affective consequences. In two experiments we presented participants with two or three visual stimuli and then, after the stimuli were no longer visible, provided an attentional cue indicating which item in memory was the target they would have to later recall, and which were task-irrelevant distractors. Participants subsequently judged how much they liked these stimuli. Previously-ignored distractors were consistently rated less favorably than targets, replicating prior findings of distractor devaluation. To gain converging evidence, in Experiment 2, we also examined the electrophysiological processes associated with devaluation by measuring individual differences in attention (N2pc) and working memory (CDA) event-related potentials following the attention cue. Larger amplitude of an N2pc-like component was associated with greater devaluation, suggesting that individuals displaying more effective selection of memory targets—an act aided by distractor inhibition—displayed greater levels of distractor devaluation. Individuals showing a larger post-cue CDA amplitude (but not pre-cue CDA amplitude) also showed greater distractor devaluation, supporting prior evidence that visual working-memory resources have a functional role in effecting devaluation. Together, these findings demonstrate that ignoring working-memory representations has affective consequences, and adds to the growing evidence that the contribution of selective-attention mechanisms to a wide range of human thoughts and behaviors leads to devaluation
Visual search for multiple targets remains efficient when supported by recollective long-term memory
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