Bitcoin Forum

I would like to know is it possible to transform an open source web browser, say Firefox, to act as a node ? May be not for bitcoin, but for some alt coin. How feasible this idea is ?

It is possible. You do not need to work on the whole browser code for that. All you need is a browser plugin. But, that would definitely be an Alt coin.

What would be the advantage?
How would you handle the potential vulnerabilities?

When browsers act as node, there will be abundance of nodes in the network, which will increase security.

Could u plz list out the potential vulnerabilities?

Could such a plugin be designed to operate on only a specific page?

Are you suggesting that the blockchain is stored in a cookie? :) (not a serious suggestion). If it was run in a plugin, then would it use port 6333 still, if so, all you seem to be doing is to ptovide an html front end imho. Storing the blockchain in the cloud could allow it to be shared, but that would create further problems.

The multitude of vulnerabilities in browsers are well documented.

No, you could implement Bitcoin in a browser with APIs available today. You would need to make a new relay protocol based on WebRTC, and have some bridges between the old and new protocols, but it would still be Bitcoin.

But what will be the profit - very small I think. It is possible of course  ;)

A bitcoin node does not need much CPU power, but a lot of disk space to store the blockchain. Typical browser plugins work on very limited amounts of data, and users would probably not want to run a plugin that consumes dozens of gigabytes on their hard disk and constantly talks to the network.
And of course the other point is very valid: What's the practical use for such a thing? Which actual problem would it solve?

Onkel Paul

Basics of a Node
1. The entire blockchain is stored on the node itself.
2. It consumes less power

Basics of a Browser
1. A browser is just a front end visualizer to the user.
2. It uses very less resources to store values in the form cookies.

A browser in my aspect can't be a node, as a plugin can't handle a blockchain. If the entire blockchain is stored in the computer where the browser is installed, then the qt itself can act as a node. Why do we need a browser to act as a node?

So, it is not possible to make browser a node. There is no possible for a light weight node in terms of memory usage.

It's feasible if it's an SPV wallet, not a full node. Storing the headers costs only a few megabytes, and transactions are extra, but wouldn't amount to much.

You even can go deeper and store hashes of chunks (2016 headers). This solution require less than megabyte and you don't need WebSQL or IndexedDB, you can use localStorage. The bad thing with this that you need extra traffic for loading full chunk (~160kb) when you need only one header (80 bytes) for transaction verification.

Blockchains of any coin can grow in giga and tera bytes over time. A node must have the memory to hold full blockchain on its own. A browser can act as a front end of a node but can't be a node itself. There is no such implementation so far yet. However, there may arise some secure vulnerabilities that can easily steal coins from the wallets. It is possible, however not going to happen.

May not be as a node, but ofcourse as a wallet. In fact, the founder of JavaScript aka co-founder of Mozilla is working on that...

https://www.brave.com/FAQ.html#collapseEight

In short, if you are thinking about building something, you are probably in the right direction...