Nexus Entrance / Board index /Reference
Nexus addresses three doors, one platform behind them

Your account, balance and orders are the same through all three. Copy rather than retype, and check the signature once you are through.

Door A nexusb2l73qzjn4slhyfxa3jvpolw7fomiz5sgyyefnsdhikaqgborqd.onion
Door B nexusma2iegzo7atzwbrwxhcdopyri3vare2twibldnlc3txqjdeb5yd.onion
Door C nexusabcd6xxpjuftr7i3uohealsg64xtgwrmznkfh3o3rkcf3raxead.onion

An address that opens is not an address that is genuine. The check that settles it takes under a minute.

The client

Short, because the correct answer is one piece of software and most of the page is about what people use instead.

The correct answer

Tor Browser, downloaded from the Tor Project directly, with the installer signature checked against their published key. Then set the security level to Safest before going anywhere that matters. Some pages break at that setting. That is the trade and it is a good one, because the scripting it disables is what most drive by compromise depends on.

What the security levels actually change

LevelWhat it does
StandardEverything enabled. The largest attack surface and the reason the other two exist.
SaferScripting off on non-secure sites, some media restricted. A compromise that mostly helps.
SafestScripting off everywhere, most media and fonts blocked. Pages look plain and behave predictably.
Never do thisLowering the level to make a slow page load does not help speed and removes the protection. This trade is always bad, and being asked to make it is a warning sign in itself.

What not to use

Mobile

Workable and worse, and worth being honest about rather than dismissive. Verification is genuinely harder, the signature checking workflow is poor, and the platform underneath gives you less control over what else is running.

The specific problem is not that mobile is insecure in the abstract. It is that the one habit this whole site rests on, checking a signature before typing anything, is inconvenient enough on a phone that people stop doing it. A tool that makes the load bearing habit annoying is a tool that removes the habit.

Tails and Whonix

Both are meaningful improvements and both are a step up in effort. They matter most for somebody whose ordinary machine is shared, monitored or otherwise not fully theirs. For a reader on their own machine who is going to do this a handful of times, the honest ranking is that pinning a fingerprint properly buys more safety than changing operating system, and it takes an hour instead of a weekend.