How do you cut online crime, tackle child pornography, halt crippling viruses and get rid of spam? The answers could lie in a £200m successor to the internet that computer experts are already referring to as the next rendition of the virtual world.

Researchers in the US want at least $350m (£175m) to build the Global Environment for Network Innovations (Geni), touted by some as the possible replacement for today's internet. In Europe, similar projects are under way as part of the EU's Future and Internet Research (Fire) programme, which is expected to cost at least £27m.

With online crime rising and traffic increasing rapidly, some academics believe it is time to have a serious discussion about what succeeds today's internet.

"There's a real need to have better identity management, to declare your age and to know that when you're talking to, say, Barclays bank, that you're really doing so," said Jonathan Zittrain, professor of internet governance and regulation at the Oxford Internet Institute.

At the moment we are still using very clumsy methods to approach such problems. The result: last year alone, identity theft and online fraud cost British victims an estimated £414m, while one recent report claimed 93% of all email sent from the UK was spam.

The backers of Geni are hoping that it can find answers to problems like this. It is supported by America's National Science Foundation and has a timescale of 10-15 years.

Many ideas revolve around so-called "mesh networks", which link many computers to create more powerful, reliable connections to the internet. By using small meshes of many machines that share a pipeline to the net instead of relying on lots of parallel connections, experts say they can create a system that is more intelligent and less prone to attack.

Dipankar Raychaudhuri, a professor at Rutgers University in New York, is working on alternative systems but says making progress is tough. "People keep trying to evolve the network, but it hasn't really changed in 20 years," he said. "Once you've built something as large and complex as the internet it is difficult to start over again."

One of Prof Raychaudhuri's projects involves short-range communication. The technology could be put inside cars, allowing them to talk to each other, and other systems, to bring long-held visions of safer, automated driving into reality.

Another option is to spread information around the planet in a different way: rather than scattering small pieces of the network across hundreds of millions of computers like puzzle pieces, each containing one tiny piece of the internet, alternative systems could be able to keep a local copy of the net. Instead of surfing in public view, users would spend much of their time wandering around inside their own computers - leaving them less vulnerable to attacks from hackers and criminals.

Millions of pounds are being pumped into academic research, bringing to mind the early days of computer networking such as Arpanet, the forerunner of today's internet. Arpanet was funded by the American government for experimental research and began operating almost 40 years ago. But while American computer scientists in the past relied on government money, they have had less support from the Bush administration, which has substantially reduced funding and channelled money instead into homeland security projects.

With those limitations in mind, some experts have warned that starting from scratch is a gamble. Jon Crowcroft, Marconi professor at Cambridge University and one of Britain's foremost internet engineers, is among those who do not believe a clean-slate approach is necessarily the way forward.

"There's a risk in doing completely blue-sky research that fixes a problem but then turns out to be useless at the things the internet did well," he said. "There aren't that many who can do a clean-slate design – and you don't want to throw the baby out with the bathwater."