Rather than bootstrapping their security, rollups can hook up with Polkadot via its Digital cores by purchasing coretime with DOT and faucet into Polkadot's multi-billion shared security. By doing so, they inherently access Polkadot's secure interoperability and might communicate with other programs running on unique cores of Polkadot's Digital CPU. https://sergioolfyq.uzblog.net/how-much-you-need-to-expect-you-ll-pay-for-a-good-polkadot-chocolate-truffles-50226503