There is very simple way to deter this. Australia does the same in their expression of interest phase. They ask for few IDs, like passport number, IELTS TRF number and credential/skill verification agency ID. All of these can be checked for uniqueness and as per their T&C you cannt apply for more than one EOI. Now for authenticity, there is one simple way. IELTS TRF can be checked automatically to be valid against IELTS database, so is passport I guess because in the immigration they do check your passport number for visa and lastly they can ask agencies like WES to provide a database access for verifying the credential information against passport ID number or other unique ID number. Australia does something similar, they also ask for EOI before main application and their system is running for quite sometime now. For someone to fake this EOI will require her a fake but valid passport number, a fake but valid TRF number and a fake but valid credential/skill verification agency ID, also they should be unique. All of them will cost time and money so it will make fake IDs costly affair.
