Well, I don’t know the exact law, but if one could claim the grand prizes anonymously, the potential for fraud by government and lottery officials would be massive. Knowing the propensity towards human beings to steal when a large enough prize presented itself, this guy would never have won a prize this massive because some beaureacrat would have stolen it and remained anonymous. In fact, that is probably what would happen every week.
Also, I do believe winners have to agree to have their names and likenesses used in advertising for said contest in order to claim their prize. But I could be mistaken...JFK
The only problem with that is those frauds can't produce a winning lottery ticket like a legit attorney working with you can.
You should photocopy a winning ticket and place it in a safe deposit bank at a reputable bank then contact a lawyer. When the time comes to presenting the ticket, the lawyer will then request it and it all can be done secretly and without fanfare. You and the lawyer wins as his cut will be a lottery in a way for him so getting a credible lawyer is pretty important. A sleazy lawyer might swindle you in some way.
To clarify, a trust will most likely be setup and the money “givin” to that. Someone (or some group of people) won $265 million in the Mega Millions lottery in Ohio recently and used a trust to claim the prize without revealing the identities of anyone involved.
Usually a group of people will do that and to ensure fairness but also done to allow anonymity.