With Gulden you send money to each other, wire it to any IBAN account, pay at Gulden merchants and enjoy a very healthy return.

Gulden

whitepaper

Introduction to the blockchain

Zero-conf double spend

Short chain double spend

Long chain double spend

Double spends

>50% attacks

Selfish mining

Side chains

Centralisation of mining

Block target

Inaccurate block times

'Jump' pools

Erratic block times

Block size limit

Denial of service/empty blocks

Transaction capacity limitation

Sybil attack

Stalled blockchain

The problems

Alternative hashing algorithms

Alteration of block target

The 'unlocked wallet' problem

The ‘nothing at stake’ problem

Bribing

Stake grinding

Quantity of staking coins

Use of old private keys

Stake build up attack

Problems with SPV wallets 

Proof of stake

Combined PoS/PoW

Multi-algorithm

Master nodes

Checkpoint server

Difficulty adjustment algorithms

What has been tried so far, and how it has failed

The naive/basic concept

The optimised/full concept

Implementation details for Gulden

An analysis of PoW² against the known flaws/attacks faced by existing algorithms

Consideration of new flaws/attacks

PoW² - an improved successor to PoW 

A proposed solution to many of the problems above

A secure 0-conf solution (Code name Prime II)

Conclusion

Witness selection algorithm

Attack probability [Naive]Biased toward PoW.

Analysis of attack probability with grinding

Attack probability analysis graph[Naive]Biased in favour of PoW.

Attack probability source code

References

Gulden 2.0 - Improving the blockchain

Gulden Whitepaper