So, I am currently doing research for a project and an interesting question was born. If I have data that I want to store encrypted, why to choose blockchain instead of a cloud provider? Since the data is encrypted, wherever I decide to store it, it should be the same in term of privacy and security, right? Because, even in the case of the cloud provider, nobody can decrypt my data except for me. Any ideas?
Storage cost on a blockchain is an orders of magnitudes more expensive than cloud storage. Bytewise you willl pay more than 1,000,000x storing your dat, so you really do not want to store it on a general purpose blockchain.
However there are services like Storj that offer upfront, fixed-term payment for storing your data and it comes with a blockchain-like guarantees, decentralisation and censorship resistance:
In Storj, the storage rent fee is paid with Ethereum tokens.
So firstly, I would have to agree with Mikko. It is very economically infeasible to store data on the blockchain, thus in most cases if you would want to use a blockchain to store data, you would make use of blockchain-like networks such as IPFS via Filecoin. These networks usually hash the data and only store that hash on a blockchain, while breaking up, encrypting and doing a lot more other "stuff" with the data. I have heard that some data is broken up into bits and distributed amongst network participants, which means no one has access to the full dataset. And on top of this, this data is encrypted etc.
So to get back to your question, storing data on the cloud is fast, easy and cheap, but a lot more vulnerable. Storing data on the blockchain (or the blockchain method) is more secure, but may lack in speed. The cost would most likely also be low using the IPFS method.
Note: When talking about vulnerability in the above statement, it is mostly in regards to vulnerability in terms of ease of access for malicious actors. Due to more security walls on the blockchain method, it is harder to break through.
Hope this helps!