Overview & status
Users are allowed to choose any node in wallet settings. We don’t no if each node is trusted or not, and it can be critical due to OTS index.
Motivation and implementation possibilities
In order to counteract malicious nodes that may receive someone’s transactions and not propagate it to the network, we should store all output transactions history in all wallets, whenever it is mobile wallet, or desktop wallet, instead of receiving last used OTS from blockchain.
Even lightweight wallets for other blockchains do so(for example Metamask for Ethereum).
In wallets that can’t store data(web wallet) we should caution users every time they unblock their wallets, that they should check transaction history of current wallet, and move funds to another wallet if they don’t find in blockchain any transaction that they made.