- The IOTA Foundation is currently implementing Mana, a system to combat Sybil attacks.
- The reputation system is used to identify trusted nodes.
William Sanders, mathematician at the IOTA Foundation, published a new post a few hours ago, which explains the exact way Mana works. Mana is a new reputation system that is integrated into pollen to fend off so-called Sybil attacks. According to Sanders, the developers are already working on the implementation for pollen.
This is how Mana works
A Sybil attack is a malicious attack on a peer-to-peer network in which a person or organization attempts to take over the network by using multiple identities to control multiple accounts or nodes. In the context of distributed ledger technology, this is a type of attack that is also well know and important for the Bitcoin and Ethereum ecosystem.
In particular, in the event of a network overload as a result of a Sybil attack, it must be clear how the network should react and who controls the network. Mana was developed to meet these two requirements for a secure ecosystem. Mana is a reputation system or a mechanism to ensure that the consensus result makes the right decisions when two conflicting transactions are voted on:
When a value transaction is processed, a quantity called mana will be “pledged” to a specified node ID. This quantity is related to the amount of IOTA moved into the transaction. The mana pledged to each node ID is stored as an extension of the ledger.
The amount of Mana in a transaction is always the same as the amount of MIOTA. This creates a system that can distinguish trusted nodes from new and thus possibly malicious nodes. Mana is thus perfectly suited as protection against Sybil attacks, as Sanders explains:
The only way to gain Mana is to convince some token holder to pledge it to you. In this sense, mana is Delegated Proof of Token Ownership. Mana, therefore, provides adequate Sybil protection because it is difficult to acquire it in arbitrary amounts.
According to Sanders there will be two different ways to calculate Mana within the IOTA 2.0 implementation. The first way is to have the Mana equal to exactly the same amount of MIOTA in a transaction existing MIOTA. Beyond that, however, there is supposed to be a second mechanism:
The second way mana can be calculated (“mana 2”) is an augmentation of mana 1 which includes not only a delegated proof of ownership but also proof of node activity. Mana 2 has a predictable evolution over time, in the sense that it is not affected by additional token transfers.
The team has implemented both variants in GoShimmer and is currently investigating which option offers robust security and maximum performance.
Is Mana comparable to a delegated proof of stake consensus?
Sanders further explains that while Mana has similarities to a Delegated Proof of Stake (DPoS) consensus, there are significant differences. Within a DPoS system, validators are chosen to create blocks, receive rewards and fees, but if they fail, everything may be lost. However, the Tangle relies on a directed acyclic graph (DAG) where there are no blocks, rewards or fees, so the comparison between DPoS and mana is limited.
Recently, the IOTA Foundation released the beta version of IOTA Streams, which reduced the size of the library and as a result increased the performance almost 100 times.