What is MultiChain Streams

The stream is the new set of functionality called "streams". Streams provide a natural abstraction for blockchain. It uses cases which focus on general timestamping, data retrieval, and archiving kind of the transfer of assets between participants.

We can be used to stream implement by three different databases on a chain:

• We can be used the key-value database, in the style of NoSQL.
• We can make time series database, which targets on the ordering of access.
•  We can identity-driven database where entries are classified according to their author.

Streams Basics:

We can create multiple numbers of streams in a MultiChain blockchain, and every stream can act as an isolated append-only collection of items. All item in a stream has the following characteristics:

• One or more publishers who have digitally signed that item.
• The Stream has an optional key for acceptable later retrieval.
• Some data, which can range from a small piece of text to many megabytes of raw binary.
• A timestamp, which is taken from the header of the block in which the item is confirmed. 

Developers can read and write stream but they don't know about the basic mechanism. Each item in the stream is representing by blockchains transaction. The number of ways to integrate the streams with multichain permissions system. The user has need permission to creates streams and the same way that assets can only be issued with certain addresses. When stream will be created it can be open or closed. Restricted to a changeable list of permitted addresses in the closed stream and who has the permission of writeable can send a blockchain transaction in open stream.

Each blockchain has an additional root stream, which specified in its parameters and exists from the moment chain created. This permit a blockchain to be used directly for storing and fetching data, without waiting for a stream to be especially created.

Streams give a natural way of backing encrypted data on a blockchain:

1. A 1st stream is used by the member to give their public keys for any public-key cryptography scheme.
2. A 2nd stream is used for announcing data, where each piece of data is encrypted using symmetric cryptography with a particular key.
3. A 3rd stream gives data access. For each member, a stream entry is created which accommodate that data’s secret key, encrypted using that participant’s public key.