The Cosmos Hub ($ATOM) has proposed an upgrade to adopt the Replicated Security feature. This is the Interchain Security feature previously called.
In the past it has been referred to as Interchain Security v1, or ICS, but going forward the team will refer to it as Replicated Security.
Replicated Security is a new feature that enables the Cosmos Hub to offer its strong security to other blockchains, also known as 'consumer chains'. With this feature, consumer chains can benefit from the Cosmos Hub's security without having to maintain their own validator sets. The cost to censor or control a consumer chain with an economic attack is the same as the cost to censor or control the Cosmos Hub itself.
Replicated Security works through the IBC protocol. The Cosmos Hub's validators can validate multiple chains at once with the same stake. In exchange for this service, consumer chains are expected to send a portion of their fees and inflation to the Cosmos Hub validators and delegators, which will then be included as part of the Cosmos Hub's staking rewards.
If the proposal passes, the $ATOM token will for the first time have a value accrual mechanism.