The beauty of the Tangle is that you can fluidly branch off and back into the network. This partitioning is key in being adaptive to the rigorous requirements of an asynchronous IoT environment. There is no such thing as always-on connectivity, as such you need to be able to make transactions and secure data even in an offline environment. IOTA makes it possible for a cluster of devices to branch off and still make transactions in an offline environment; utilizing different communication protocols (ZigBee, Bluetooth LE, etc.) for the P2P communication.
Could this be done with datachains in SAFE as well?
It is the network, so being offline means you are no longer connected to the SAFEnetwork. SAFE is the network, not some APP or storage system that is located online.
Its more of a question for the APPs being developed to run the IoT devices and the job they are intended to do.
For SAFEcoin its security requires that the transaction occurs with the approval of two distinct groups so at this time there isn’t any system for offline transactions for SAFEcoin. Now a system of escrow might be possible to allow offline transactions or maybe another system. It might be possible for IoT devices to use a third party account for future microtransactions to allow offline transactions with a form of credit. But again this is the realm of APPs and not the network.
What if the “offline” partition was bunch of IoT devices that formed a small SAFE Network and did have two groups and just transfered SAFE coins between themselves until connecting to the larger network? Perhaps such a mini network wouldn’t really be secure though.
Once that small network joined the main network then the groups would invalidate those coins because your little network nodes would be spread across XOR space and lose consensus over those coins it “created” and those “coins” cease to exist.
It would certainly be useful for an app to be able to sign some transaction offline. But then we’re back to the double-spending problem, not sure how or if IOTA tangles actually solve this. I would imagine two identical offline tangles could be run by two different sets of IoT devices where each spend the same tokens, leading to an issue when they try to merge with the larger network.
I’d expect that for IoT that needs offline transaction then a system of “credit” and a 3rd party creditor would be a better avenue to go down. In other words a separate ledger system that the IoT devices can pass amongst themselves and redeem for SAFEcoin (or pay if in debt) from/to the 3rd party creditor when they rejoin the network.
Interesting, so perhaps the state channel concept could be implemented for SAFE also, or at least something inspired by it. Perhaps compute need to be implemented first though, or maybe there’s another SAFE way to do it.