Currently, indirect_call is initiated by enclave_account in indirect_call_executor, and the nonce of the account is read from storage. When a block has only one indirect_call, the nonce handing is no problem(read from stroage), but if there are multiple indirect_call in a block, a too low priority error will occur. Because the nonce will not increase before the indirect_call is executed.

This requires us to have a method to adjust the value of nonce. The solution can be:

• We can read the number of pending_trusted_calls initiated by enclave_account from top_pool (here I will call it pending_tx), current_nonce plus pending_tx should be the value we need. Here are some code for reference

Sign call:

Adjust nonce:
https://github.com/paritytech/substrate/blob/ac176294e647f0eabd0970537567bf37ded00360/utils/frame/rpc/system/src/lib.rs#L180-L211