- How often
- Every session, straight after copying.
- How long
- Five seconds.
- What it prevents
- A near miss address, which is what people mean when they say an address was cloned.
- If you skip it
- You are relying entirely on the signature check, which is a reasonable fallback and a thin one.
- How you notice you stopped
- You catch yourself recognising an address rather than reading it.
How people actually read a long string
Shown fifty six characters of unpredictable text, almost everybody reads the first four or five, glances at the end, and accepts it. That is not laziness, it is how reading works. Long random strings get sampled, and the samples people take are the boundaries.
Forgery is built around that. Matching a recognisable opening is cheap, matching the middle is not worth the compute, and matching everything is impossible. So the differing characters sit exactly where sampling does not reach.
| Matching | Cost to produce |
|---|---|
| Four or five opening characters | Seconds to minutes on an ordinary machine |
| Seven or eight | Hours to days, still entirely practical |
| Twelve or more | Not feasible |
| The whole address | Impossible, and everything rests on this |
The one exception
Something on your own machine replacing an address between the copy and the paste replaces the whole string rather than resembling it. That is caught immediately by checking the first and last several characters of what actually landed in the field, and it is the only situation here where the quick check is the right one. It applies to payment destinations as much as to addresses.
Things that are not the problem
- Confusable characters. The alphabet used here excludes visually ambiguous pairs by design, so an address that looks slightly off genuinely is off. Never a font issue.
- Case. These are case insensitive, so mixed case is formatting rather than a different address.
- Length. Always fifty six characters before the suffix. A shorter one is from a retired protocol version that stopped resolving years ago.