A Hash based digital signature utilizes a one-time signature (OTS) as the signature’s main building block, and converts it to a many-times scheme, in order to sign a greater number of signatures. Within the context of known constructions, the size and cost of each signature rise as the number of needed digital signatures grows. When real world applications are considered, a considerably large number of signatures are needed, and these signatures can occasionally get quite large. As such, it is inarguably clear that post-quantum signatures relying on hashes require more computation resources, as well as larger sizes, when compared to classical signatures.
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