The first paper builds on the paper released in 2014. This paper provides a formal mathematical proof that what is supposed to occur on the network will actually occur. It states that the network will not fork into two competing networks and that the network will never be stuck while processing transactions.

The second paper wants to improve on previous XRP plans. The paper introduces an algorithm that will support a richer array of validators. According to the paper, XRP can be thought of as some kind of voting system. Each node that stores that Ripple transaction history will get a vote on what will happen next.

More details: Ripple Paper Promises New Support For Ripple XRP - Major Upgrades for the Third Most Valuable Crypto Coin