Method for designing a processing architecture (10, 200) for a set of operations performed on data, some data requiring a level of protection, the set of operations performed on data requiring a level of protection greater than a threshold level of protection comprising at least two sub-sets of operations which are capable of being carried out in parallel, characterised in that the method comprises a step of: - determining the different sub-sets of operations of the set of operations, each sub-set comprising operations to be performed on data requiring a level of protection greater than a threshold level of protection and each sub-set of operations being capable of being carried out in parallel with the other sub-sets of operations, - determining, for each sub-set of operations, the highest level of protection required by the data on which the operations of the sub-set are performed, and - generating, for each sub-set of operations, a processing block (12, 206) in the processing architecture (10, 200) to be designed, the processing block (12, 206) comprising a computation sub-block (21, 244, 246, 248) dedicated solely to the execution of the operations of the sub-set on data to be processed by the processing block (12, 206) whose level of protection depends on the level of protection determined for the sub-set of operations in question, and a protection sub-block (22, 250, 254, 258) capable of protecting the data to be processed by the processing block (12, 206), and - generating at least one switch (20, 204) capable of routing the data to be processed to each processing block (12, 206), wherein the method is further characterised by the steps of: - determining the operations to be performed on data whose level of protection is lower than the threshold level of protection, and - generating, for each of the determined operations, a processing unit for the operation, the processing units being separate from the processing blocks (12, 206), - determining, from among the operations performed on data whose level of protection is lower than the threshold level of protection, redundant operations, and - eliminating, for the determined redundant operations, one of the two redundant operations. - determining the different sub-sets of operations of the set of operations, each sub-set comprising operations to be performed on data requiring a level of protection greater than a threshold level of protection and each sub-set of operations being capable of being carried out in parallel with the other sub-sets of operations, - determining, for each sub-set of operations, the highest level of protection required by the data on which the operations of the sub-set are performed, and - generating, for each sub-set of operations, a processing block (12, 206) in the processing architecture (10, 200) to be designed, the processing block (12, 206) comprising a computation sub-block (21, 244, 246, 248) dedicated solely to the execution of the operations of the sub-set on data to be processed by the processing block (12, 206) whose level of protection depends on the level of protection determined for the sub-set of operations in question, and a protection sub-block (22, 250, 254, 258) capable of protecting the data to be processed by the processing block (12, 206), and - generating at least one switch (20, 204) capable of routing the data to be processed to each processing block (12, 206), - determining the operations to be performed on data whose level of protection is lower than the threshold level of protection, and - generating, for each of the determined operations, a processing unit for the operation, the processing units being separate from the processing blocks (12, 206), - determining, from among the operations performed on data whose level of protection is lower than the threshold level of protection, redundant operations, and - eliminating, for the determined redundant operations, one of the two redundant operations.