Computer software is not going to stop black market sales of pot by legal producers / retailers. The government is going to spend all their new tax revenue attempting to track production from seed to sale. If they want to use a high tech method require all producers to get their seed from a government lab and insert a genetic marker designated to each producer. Audit the crops to ensure no illicit pot is being grown with the crops. If any end user pot is found outside the legal system fine the producer or pull their licence.

Software is simply an accounting method that can be cheated, just look at the FDA's infallible quality control software that was used in India to ensure the proper handling of defective batches...one company was found to tamper with the software approximately 5700 times.