Current trends of the decentralized software development makes new applications and platforms to appear every day. One exiting direction is to build decentralized or P2P storage systems on the top of exiting Blockchain technologies, like SWARM on the top of Ethereum. Certainly these technologies are pretty much in the experimental phase, despite it is interesting to evaluate which advantage or disadvantage can have a P2P storage system for example comparing with a classical cloud storage.
- Zero downtime: well cloud systems have got surely the high availability characteristic. The same property can be found however at a P2P storage as well. Copies of a document or data is generally stored on a lot of nodes: if an adequate distribution algorithm is implemented to store copies based on availability and geographical location of the nodes, than high availability can be guaranteed.
- Fault tolerance: The same is true for fault tolerance. Adequate distribution of the copies of different pieces of information on different nodes can realize a highly fault tolerance system, similarly as at a Cloud storage.
- Scale up - Scale down: well from the point of scaling up or down the two systems have got more or less the same characteristic. One can always get some more storage with a couple of clicks, one can set some storage free similarly.
- DDoS resistance: Well Cloud is more or less centralized or at least based on several huge centralized cloud center, as a consequent they are not so immune for a DDoS attack as a fully decentralized P2P network.
- Censorship-Resistant: Possible censorship is a major characteristic even of a cloud storage system. As the cloud service itself is operated by a large company like Microsoft or Amazon, there is always an easy possibility for censorship. On the contrary on a P2P system for a successful censorship at least 51 or perhaps 100% of the resources are required that is economically pretty expensive.
- Security: Security is a big issues for a P2P storage system. As our data is stored overall of the world, the only way to provide professional service is that the data itself is so highly secured that even the hoster of the node can not make the decryption. As it is theoretically possibly to realize such a strong decryption mechanism, the question is if accessing the data remains performant enough.
- Price: The second big question is the price of such a system that can be influenced by two factors. On the one hand a P2P storage can be more expensive than a Cloud storage as most of the data are stored in more copies. On the other hand, a P2P storage can be cheaper as well as most of the resources are extreme cheap, meaning that they are stored on resources that otherwise would not be utilized.
As a conclusion, I would say the major risk is the security - performance characteristic. If these two properties can be realized in a way that is comparable with a Cloud storage or at least acceptable to the market, than there is a chance that in a year or two decentralized P2P storage services appear.