How Should Political Parties Be Funded?

In a democracy all political parties require funding to support their campaigns.

In some countries private companies, interest groups and private individuals give vast sums to their chosen party.

Is it naive to think that large donations are given with no strings attached?

Do you support the state funding of political parties or the banning, or severely restriction, of advertising campaigns?

Do modern campaigns fail to address the real political issues and stifle intelligent debate?