Re: Government should implement blockchain technology to prevent corruption.
Blockchain is a good technology that will be use as a tool of transparency to every transaction being done. The government should know and develop a system like this on their system. This will eradicate corruption or transactions being made under the table because there will be a transparency on every transactions and how much money is involve. The budget of the people will be obviously utilize to its intended purpose. Would you agree with this idea?
But we can't expect a corrupted government to take steps for anti corruptions. 
As you said the blockchain can be used in all the transaction for the government related which can help us to have corruption free transactions but the politicians need to implement this system but if they do then they can't make money anymore so they will never do this.
But all the governments are not corrupt. There may be few / some governments which were not so honest so the funds were being diverted to their own pockets. But When an honest government comes to power and strictly ensures the reaching the benefit to deserved entitled one: then the results are very much amazing.
In past four year Indian Government took decision not to pay the social welfare benefit payment via fiat. It ordered crediting their accounts and in four years Rupees 9000 million were saved because these were going to the corrupt people may be without the notice to the top leaders previously.
So it depends on the intentions of the Governments. If they really want to progress their country; they will have to accept digital based transactions system.
Do you think that Current Indian prime minister helped the people to have anti corrupted nation? Nah! they just converted all other politicians money into their pocket through demonetization,best of the corruption in the recent days.