> which requires keeping the keys secret against a lot of attacks and not losing them Piece of paper in a safety deposit box (maybe even at 2-3 different banks

> which requires keeping the keys secret against a lot of attacks and not losing them Piece of paper in a safety deposit box (maybe even at 2-3 different banks) would do this just fine, but you'd have to know it was going to be worthwhile enough to have bothered. > managed to pick the peak to sell at Just sell bits of it here and there to spread the risk around.