On Wed, 27 Nov 2019 18:12:30 +0000, Martin Brown
wrote:

On 26/11/2019 21:31, Steve Walker wrote:
On 26/11/2019 12:16, whisky-dave wrote:
On Saturday, 23 November 2019 14:50:29 UTC, Alistair Tyrrell* wrote:
In article ,
says...

I'd be wary of any 4 digit code...

We had an aged relative who was admitted to hospital. When a little
better he wanted some stuff, but lost his keys on admission...
We assumed warden or neighbour would have spare key. They didn't...

I got the 4 digit code at second try. I wonder how many other dwellings
in the same complex had identical or very similar codes? So the last 4
digits of his land line would probably have been more secure.

It is a common vulnerability.

Apparently many people have set a code of a memorable year
such as DoB or marriage. So a high percentage of all
keysafes have the first two digits set to 19 meaning the
thief only has to twiddle wheels 3 and 4.

User error then.
The easy way to get around such simple people is to tell them to put
the code in backwards making 19 the LAST 2 digits xx19
Still not the best solution.

Parents' house in France (now sold) had the combination 1815 (Battle of
Waterloo).

The other thing to watch on the push button models of keysafe is that it
doesn't matter what *order* you press the buttons in so long as you only
press the right ones. This makes a 4 digit code a bit weak.

You can set a five digit code on such devices which makes it secure
enough (although not if you set a pair to 1,9).

What do you mean by "secure enough"?
The number of combinations of 4 digits is (10x9x8x7)/(4x3x2)=210.
For 5 digits it's (10x9x8x7x6)/(5x4x5x2)=252, which is hardly better.

There are videos of how to crack the code in seconds by feel, but I've
tried them on a new keysafe without success. The methods probably work
if the keysafe has been in use for years with the same combination and
the grooves have been worn into sloppiness.

It wouldn't take too long to try all 210 combinations of 4 digit
codes, bearing in mind that it doesn't matter what order you press the
buttons.
--
Dave W