With a dummy account, I have been exploring Spring, the Nostr browser, for more than a couple of month. It's much more than awesome. Almost the whole of Nostr comes under the purview of a single app. Just wanna be sure it's surely secure to entrust worth my private key. Should I feel assured, nostr:npub1gcxzte5zlkncx26j68ez60fzkvtkm9e0vrwdcvsjakxf9mu9qewqlfnj5z? 

Also nostr:npub1xdtducdnjerex88gkg2qk2atsdlqsyxqaag4h05jmcpyspqt30wscmntxy, would you please explain?