I have recently discovered some blockchain based storage technologies like Storj and Sia.

I have vaguely understood that they rely on their own blockchain with their own cryptocurrency.

  1. But why are they not relying on preexisting blockchains like ethereum which are designed to be multipurpose ?

  2. What are their exact working principle ? Indeed up to now I was under the impression that storing data on a blockchain is very costly.

  3. How are they different from IPFS and Swarm, which to my understanding are protocols for decentralized storage, but that do not rely directly on blockchain technology ?

Cheers !

Edit: I have also read this answer, which brings a lot of good elements of understanding, but I am still missing something in terms of seeing what Sia and Storj bring that IPFS or SWARM did not already have.

  • Possible duplicate of What is Swarm and what is it used for?
    – niksmac
    Apr 3, 2017 at 15:17
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    Thank you for your comment. In fact it is not a duplicate since the main topic is to understand what is new in sia and storj, not what swarm and ipfs are used for. As you may have noticed i even cited the question about swarm and ipfs in order to underline that what i am looking for is not found there
    – mhham
    Apr 3, 2017 at 15:19
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    Even so, recommendations and comparisons are generally not welcomed in SE.
    – niksmac
    Apr 3, 2017 at 15:22
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    I may have not expressed myself clearly in the question. i am not looking for recommendations but rather trying to underdtand how these new blockchain based storage technologies differ from the already existing protocolos ipfs and swarm
    – mhham
    Apr 3, 2017 at 15:50

7 Answers 7


I don't agree at all. Plus, @Meije is from Storj Team.

IPFS and Swarm are not just an idea but the most advanced technologies/protocols in decentralised blockchain based storage.

IPFS and Swarm are being used by the blockchain community.

Swarm: Swarm is part of the Ethereum stack http://swarm-guide.readthedocs.io/en/latest/

IPFS: https://github.com/ipfs/ipfs A lot of LIVE projects are using IPFS

Updated comment (to reply to @mhham):

To make it quick - Swarm and IPFS are both implementing a solution for efficient decentralised storage layer. They are very similar - they are based on a different community and a different low-technical aspect.

IPFS uses a DHT (Distributed hashed table) whereas SWARM an immutable content addressed chunkstore.

SWARM is integrated into Ethereum - therefor it can use the smart contracts and the entire protocol.

  • Thank you for your comment. Could you give me more details about Ipfs and swarm. It seems indeed that the previous answer is quite biased !
    – mhham
    May 19, 2017 at 18:53
  • I've just updated my comment. Please let me know if you need further information. May 20, 2017 at 11:29
  • Thanks you for updating your answer. Things are a little clearer now. Still, could you please develop on the difference between DHT and SWARM's implementation, or if it is too technical suggest some ressources thats I could read. I am really excited about the latest advances in decentralized computing, for both philosophical and technical reasons. IPFS and SWARM really seem to me like building blocks for what is coming, but I still have trouble grasping the technical aspects behind.
    – mhham
    May 21, 2017 at 22:23
  • @julienbouteloup: you conveniently decided to not address Sia at all in your "response". Jul 7, 2017 at 2:22
  • Correct. Because I never talk about stuff that I don't know. I'll investigate it and update my post. Jul 13, 2017 at 22:16

First of all, I am not very familiar with Ethereum Swarm. But I do know Swarm is a strong competitor for IPFS. There is an argument whether to build more functionality into base-layer blockchains themselves or to build it into protocols that live on top of the blockchain. Apparently, Swarm and IPFS take different strategies as Swarm (the second strategy) runs on the EVM layer while IPFS is at the bottom layer independent of the blockchain technology. One big fallback of IPFS is the lack of incentive mechanism. Today Filecoin is more of a hit compared to IPFS since Filecoin (the first strategy) achieved the incentive mechanism with its own blockchain consensus algorithm that is closely related to Proof of Replication (PoRep) and Proof of Space-time (PoST).

I'll talk more about Storj, Sia, and Filecoin here. Sia is one of the earliest implementations for a Distributed Storage Network (DSN). All personal files to be uploaded at the client end is supposed to be encrypted first since the auditing on data storage, a.k.a, proof of retrievability (PoR), is publicly verifiable. They achieve this via the Merkle tree and probabilistic auditing by exposing the random sampling data block. (You can see why it is important to encrypt the data first)

For Storj, private verification is used. That is, the data owner is supposed to do the auditing job here with pre-generated nonces/salts and the classic Hash(block, nonce/salt). BTW, your password also uses this "add salts" method to minimize the possibility of a brutal-force attack. One problem is fairness handling. What if the data owner and storage provider have a dispute? Storj in its current implementation uses somehow "centralized" bridge servers to resolve this. And also the bridge server plays the role of a private verifier. Another problem is that the number of pre-generated nonces is limited, which restricts the frequency of auditing (PoR).

Now let's focus on the Filecoin (IPFS). The Protocol lab developed IPFS first and now is working on Filecoin mostly. As I have said, Filecoin is basically an "advanced" IPFS version with blockchain incentive mechanism and even the off-chain trading market for file storage. Filecoin uses some very cutting-edge technology closely related to the cryptography. For starters, Filecoin (and IPFS) not only considers the files that can be encrypted. That's correct. Only personal files are assumed to be encrypted correctly. For public data like the blockchain itself, one simply does not have the incentive to encrypt it correctly. Filecoin takes into the problem of encoding different replications of public data into consideration. In other words (encryption is also some kind of encoding, but not suitable for public data), Filecoin solves the problem that the storage provider can collude, outsource or simply do whatever that causes the deduplication of public data and earn more money (IPFS did not solve this). The technology used is called Verifiable Delay function (VDF). Summarizing from a very high level, it simply takes the property of an hour-glass function such that it is simply impossible that the storage provider generates the auditing proof (PoR) on the fly. And they call it Proof of Replication (PoRep) in this case. Notice the underlying PoR within the PoRep algorithm they used, at least in the white paper, is also Merkle-tree based probabilistic auditing, very similar to the one that Sia used. On the basis of PoRep, the Filecoin paper takes one step further to formalize the Proof of Space-time (PoST), which takes in another temporal dimension. Basically, they make use of incrementally verifiable computation, a.k.a, proof-carrying data to recursively and continuously compute the proof within a time period, e.g., 30s, which is also the block generation time as well as the leader election time (similar election mechanism to Snowwhite and Algorand) for Filecoin blockchain. One mature implementation is the ZKSNARK that Zcash uses, although ZK is an optional feature here. Unfortunately, the Protocol lab has not released any performance data yet.


Great response.

Just wanted to add that IPFS is more than an idea at this time with it used for file sharing or streaming with some blockchain beginning to make it indexable, searchable, uncensorable, and add features to it e.g. atmos coin plan with ipfs demo at http://afix.io/#/v/

Furthermore, the other claim made implying higher volumes of data through centralized bridges are necessarily faster than fully decentralized Sia are misleading as Sia has been tested for upward of 300 mbps speeds https://www.reddit.com/r/siacoin/comments/5plkgg/attempting_to_replicate_300_mbps_bandwidth_in_sia/dcun1co/


IPFS are more protocols but lacks the incentivization mechanism that SIA and Storj have.

Filecoin has been the planned incentivization mechanism from the beginning.


Just to add a few notes here.

IPFS is a used a lot currently but it's still missing the incentives part which is planned (Filecoin). This means nobody will have any incentive to host your data for you - basically whatever data you want to store in IPFS you have to host on nodes you control. In that sense it's not currently decentralized, although you can of course run multiple nodes in multiple geographical locations and have the data (and access to it) decentralized.

As I see it, Storj and Sia are approximately at the same level of abstraction. Sia uses its own coin for incentivizing (paying) users to host other people's data, Storj decouples that part and supports different means of incentivizing.

Swarm is still under construction and is not ready for production, but when it is it will have the advantage of being tightly coupled inside the Ethereum ecosystem.


https://medium.com/@ppio/differences-between-ppio-filecoin-storj-20cdf7b3b02e This article compares Filecoin, Storj and PPIO.

  • Better if you can quote some of the useful content from the linked post. Linked only answers are not encouraged. Apr 8, 2019 at 5:22
  • Sia is decentralized and has it's own blockchain to handle all the contracts, the blockchain is kept going by miners that mine SC.

  • Storj is distributed and is payment agnostic, the payment layer is decoupled from the entire storage system. Storj will soon move over their tokens to the ETH blockchain due to the high counterparty fees. This will also open a large number of possibilities for smart contracts. Storj is distributed because although the farmers are decentralized, the main bridge server that handles the contracts between the farmers and the renters is centralized. There are some large performance and maintenance advantages of having a centralized bridge such as the ability to handle much greater volumes of data compared to SIA, however, in the near future federated bridges will be implemented which allows other people to run synchronized bridges. This will make Storj much more decentralized.

  • IPFS are more protocols but lacks the incentivization mechanism that SIA and Storj have.

  • Swarm is just a idea at the moment and does not have a functioning network, we will have to see what the future brings.

  • It is important to note that building a large network with lots of people renting out their disk space is very hard, you don't just step-in and take-over so projects as Swarm will have to not only be attractive for these people, the entire process of setting everything up must also be user friendly.

  • As i mentioned above storing data directly on the blockchain is not viable.

  • So no user data is stored on the blockchain, in the case of SIA only the contract hashes are stored on the blockchain as far as i know. For Storj only the token runs on the blockchain right now, all data contract negotiation is handled by the bridge.

-On your last comment, IPFS and SWARM don't have anything at the moment, they are just ideas, Storj and SIA already work.

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    (Meije Sibbel): Nice fake/scame comment from Storj Team ! storj.io/team.html It doesn't sound good for your ICO if you guys lie like that. I'm glad I did investigate before putting money in your scam ICO! IPFS and Swarm are not just idea but the most advanced technologies/protocols in decentralised blockchain based storage. They are being used by the real (not scammers) developers from the real blockchain community. Swarm: swarm-guide.readthedocs.io/en/latest and it is part of Ethereum ! So please, stop it ! IPFS: github.com/ipfs/ipfs May 19, 2017 at 15:13
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    @julienbouteloup If someone truly believes in something it becomes real in their little bubble? Jun 2, 2017 at 11:57
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    True. I'm looking forward to seing the new web which will punish trolls, liars and fake news in generals - based on decentralised voting systems leveraged by incentives and punishments on the blockchain. Jun 2, 2017 at 12:02
  • SWARM is totally useless, right. That's why I'm grinding it on Ropsten right now. Fake news. Jul 7, 2017 at 6:56
  • 1) So the bridge has all metadata where my files are stored. How can I get this metadata from the Bridge, that I do not relay on a single point of failure? B/c if the bridge goes down I have no clue where my files are, right? 2) Is there any other bridge then the bridge from StorjLab?
    – Ini
    Nov 5, 2017 at 12:48

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