This represents the simplest and most straightforward scheme. The commitment is inserted into the first OP_RETURN
output of the witness transaction in the following way:
34-byte_Opret_Commitment =
OP_RETURN OP_PUSHBYTE_32 <mpc::Commitment>
|_________| |______________| |_________________|
1-byte 1-byte 32 bytes
mpc::Commitment
is the 32-byte Tagged hash resulting from the MPC tree which is covered in detail later. Hence an opret commitment will have a total size of 34 bytes.