In the setting of secure multiparty computation, a set of parties wish to to jointly compute some function of their input (i.e., they wish to securely carry out some distributed task). The joint computation should be such that even if some of the parties maliciously collude and attack the other parties, certain security properties like privacy and correctness are preserved. Recently, broad impossibility results have been proven that show that unless an honest majority or trusted setup phase are assumed, it is impossible to obtain protocols that remain secure under concurrent composition (where many protocol executions take place simultaneously). These results hold both for the case of general composition (where a secure protocol is run many times concurrently with arbitrary other protocols) and self composition (where a single secure protocol is run many times concurrently). One approach for bypassing these impossibility results is to consider more limited settings of concurrency that...