Hello, members of bitsharestalk!

My name is Ray and lately I've finished an article about the history of Proof-of-Work, where I've tried to mention every algorithm that shifted the development and adoption of cryptocurrencies, such as:

- The Hashcash project
- Moderately hard, memory-bound functions
- Secure hash algorithms (SHA-2, SHA-3)
- Scrypt and its versions
- X11
- Momentum
- Cuckoo Cycle
- CryptoNight

Of course, the tech under the Bitshares was mentioned as well

Another memory-bound PoW function based on different principles was Momentum, implemented in BitShares. It is very simple:

For example, we want to sign data D. First we get H = Hash(D), where Hash() - is some cryptographic hash-function
Let us find such values A and B that BirthdayHash(A + H) = BirthdayHash(B + H), with BirthdayHash() being a memory-bound function, as scrypt.
Now, if Hash(H + A + B) < TargetDifficulty (read: begins with n zeros), than it is finished. Victory! Otherwise, go back to step 2.

I'll be happy if you take a look at it and share your thoughts in the comments!

The article is divided in two parts:

Part 1: https://bytecoin.org/blog/proof-of-work/
Part 2: https://bytecoin.org/blog/proof-of-work-part-2/