Back-Step blockchain is different to the blockchains known in Bitcoin and other currencies based solutions. It does not need proof of work. Therefore it does not need a nonce field in the header. There is no proof-of-work required. A different technology was invented to proof the  authenticity of a chain. Now a faked chain can be detected easily, without a lot of work. Several other advantages will be shown later.

How do we do it? We replace the nonce with another value, which we call back-step value.

From the current block it is easy to calculate the value of the previous block and the previous block and so on. A whole chain of backward linked values can be built and verified. The mathematical operation is easy and used in an application to verify the backward integrity of the chain.  

Calculating from the current back-step value to the one required for the next block is practically impossible.  This sounds familiar to what a hash can do. Actually any function with a one way property would work. For the back-step blockchain we use a function where input and output has the same length. Such a one-way function can be constructed in many ways. In the products we use a function, that is significantly faster compared to a hash.

Now we have two values in a chain, the hash value running from the first block to the current block and the back-step value running backwards to the first block. This is where the name Back-Step Blockchain comes from. 

A back-step blockchain can be copied on the network to other nodes, it’s consistency can be verified by everybody and network nodes are not needed for security.

Now, we got rid of proof-of-work. 
What are we doing with the saved electricity now?

Next, see the backstep generator.