Blockchain-based Cloud Computing 1: Into the blue
Tags: blockchain, cloud, innovation
Published: 2022-04-19 08:51:39

Yet another domain we force the infamous Blockchain upon? Maybe, but hear me out. Blockchain and Cloud are two buzzwords everyone knows, though only few really know about. This fact, of course, is more than understandable with the shire amount of information, innovation, and cat videos, which reaches us over the world wide web every single day. With that said, we may not only loss the overview of it all, but also the ability to combine different technologies and see possible synergies between them. So, what Blockchain and Cloud are and why, and how they could profit from each other I want to elaborate within this blog series.
 
## The Basics
First up, what are we talking about here? Described in the simplest of terms:

> A *Blockchain* is a sequence of blocks, which are linked cryptographically. Its main characteristics are *decentralization, immutability, transparency, persistency, auditability*, as well as *security* and *privacy*. 

> A *Cloud* is an on-demand network access of configurable computing resources enabling individuals and enterprises to pay only for the resources or services they use.

Two very fascinating and promising concepts that have already proven themselves in implementations like the Bitcoin or Ethereum Blockchain and the Azure or AWS Cloud. Yet, why stop there? How could the Cloud benefit from the Blockchain and vice versa?

## The Benefits of Cloud
When working with information systems there are almost always the same layers involved in the process beautifully illustrated by well-known models like the OSI-Layer. We start at the *bottom* with our physical devices and work our way upwards to the final user interface, where the user can only imagine what kind of iceberg, we – the technicians behind it – are dealing with. And now, behold, here comes the Cloud with its innovative service models IaaS, PaaS, SaaS, and many more variations. 

What those *aaS* aka *as a Service* models do for the customers of the Cloud provider is to *provide* parts of the earlier mentioned iceberg and therefore a split of responsibility. For example, in IaaS (which is short for *Infrastructure as a Service*) the provider provides the infrastructure, the hardware running your software if you will, and takes that responsibility in their capable hands. Similarly, the platform or the whole service offering can be outsourced and taken care of a Cloud provider.

## The problems of Cloud
It almost sounds too good to be true. I do not know many peers in my field, which love setting up a network, configure all devices, setup firewalls and VMs, and then code the back- and frontend like going on a Sunday walk. Usually, everyone has their preferences when it comes to this vast domain and with Cloud one can focus on exactly that. So, what could possibly go wrong? 

Current Cloud storage architectures have the big disadvantage of being a centralized data storage, which compromises server security, and creates the need for a trusted third party. Yet, who defines trust? Who can make sure that the data persisted today will still be as available and untouched tomorrow? This is where Blockchain comes into play. 

## Blockchain-based Storage
As stated earlier, Blockchain provides multiple interesting features, some of which now probably seem more useful than before in the context of Cloud computing. In fact, recent research discussed Blockchain-based Cloud services for domains like data management, access controls, resource management, data security as well as service management, and many more, across all the three service models IaaS, PaaS, and SaaS. 

Each of those models have their unique target audience with their own requirements towards the system. Yet, something almost everyone uses daily is data auditing and sharing schemes as *Storage as a Service* a concretization of IaaS. Especially considering the growing network coverage, Starlink, and 5G everyone wants to have access to their files from everywhere. This is where Cloud Storage comes into play. However, how can one ensure what really happens to the files uploaded? 

The basic concept is elaborated in [Blockchain-based solutions for Cloud computing: A survey](https://linkinghub.elsevier.com/retrieve/pii/S1084804521002447) like this:

> […] the encrypted data is stored at a Cloud, and the meta-data about the stored data is embedded into a Blockchain along with the access control permissions. The data storage and retrieval requests are sent as transactions (*𝑇𝑑𝑎𝑡𝑎*) to Blockchain, and similarly, the changes in access control policies are also requested through transactions (*𝑇𝑎𝑐𝑐𝑒𝑠𝑠*). During the verification of *𝑇𝑑𝑎𝑡𝑎* for data retrieving, the access policy stored in the Blockchain is used to check whether the transaction initiator has necessary permissions to retrieve the data. As meta-data about the data and all the actions performed on the data are recorded in the immutable ledger this model ensures correct data auditability. Since the access control rules are stored in the Blockchain, the model provides fair data sharing and policy verification.

> One could not just profit from this new way of managing data and files within the Cloud in a private context, also Electronic Health Records (short EHR) could be tracked in a similar way. This would ensure a tamper free environment and transparent access, where access could be restricted for certain users for a certain period of time using smart contracts. And keep in mind this is only one of the many *as a Service* forms Cloud has to offer. 

## Conclusion
Maybe it has more of a fun side project character to it and does not really serve any practical purpose right now, but what it does is generating more knowledge, show bad practices, and/or open up a whole new world in tech. Whatever it will be there is always a benefit when striving for something great as great intension will always do. With that said, I am looking forward to presenting to you part two of this blog series, talking about hands-on software solutions, very soon!

For more insights feel free to consult my sources on this topic: 
- Blockchain-based solutions for cloud computing: A survey (2021): ScienceDirect, [online] https://linkinghub.elsevier.com/retrieve/pii/S1084804521002447 [accessed on 03.03.2022].

- Sahu, Mayank (2021): Blockchain vs Cloud Computing: Difference Between Blockchain and Cloud Computing, upGrad blog, [online] 
https://www.upgrad.com/blog/blockchain-vs-cloud-computing/ 
[accessed on 03.03.2022].

Photo by [Aleksandar Pasaric](https://www.pexels.com/de-de/@apasaric/) on [Pexels](https://www.pexels.com/de-de/foto/blick-auf-das-stadtbild-325185/) 🎉