# Security

To satisfy all kinds of applications, Paralink offers 3 security models with different cost, convenience and security characteristics.

# Simple Oracle

Paralink Nodes can be used as a multi-chain oracle from any 3rd party data source by any developer.

Pros:

  • Very easy to implement (just PQL definition)
  • Cheap and fast
  • Ability to source and validate multiple information sources
  • Callback support for all blockchains, without need for bridges

Cons:

  • Requires trust in node operators
  • Only suitable for applications that don't have financial impact

# Trusted Oracle

Simple Oracle can be upgraded by the virtue of cryptographically signed PQL results with ECDSA private keys from reputable data providers.

Pros:

  • Suitable for Prediction Markets, Insurance, Governance and Gambling applications
  • Easy to implement (PQL + Signing Proxy Contract)
  • Cheap and fast
  • Ability for established data vendors to sell their services on Paralink Network
  • Callback support for all blockchains, without need for bridges

Cons:

  • Single point of failure

# On-Chain Consensus

For applications that require the highest level of security, without having to rely on a single source of truth.

Pros:

  • Suitable for Money Markets, Derivatives and other high-stakes financial applications
  • Relatively easy to implement (PQL + Relayer Quorum + Bridge)
  • On chain aggregation and validation guarantees
  • Highest robustness and data quality

Cons:

  • Requires the use of bridges, ie. Polkadot <> Ethereum, so not all chains are supported (yet)
  • More expensive due to the costs of on-chain coordination