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Beginner with a Sentry. The story of zero progression.

PostPosted: Sat Sep 23, 2017 12:15 pm
by Traviality
A week ago I moved my mother out of her house and had to "inherit" some of her many hoarded possessions. One of those things was a Sentry Fire Safe.

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After a bit of digging I'm fairly certain it's a SFW123CS. Luckily, my mother never noticed the sticker with the serial number on it on the underside of the dial, so I have that and can get the combination from sentry if needed. However, I don't want to pay the fee and my mom insists nothing important is in there. That's probably true, but she has locked her purse in her car almost every other month for the past year, so who knows what could be in this thing. I also have the last number in the combination already.

This was laying on the floor behind the safe.

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A ripped piece of paper that obviously got wet at some point. My sister is also 100% that 35 is the last number as she is around the house more often than me and has opened it a bunch in the past. She spent about an hour trying to remember/guess the first two numbers to no avail. So instead of paying someone to open/help me open a safe that probably contains nothing, I figured I'd give manipulation or brute forcing a shot.

I've spent almost every night this week reading up on manipulation:
How to manipulate safes for beginners by Daggers
Safecracking for the Computer Scientist
National Locksmith's article on Old Sentrys
And I even went and found cached versions of pages no longer available like Mark Bate's interview about different gate indications
Plus countless other guides, posts, and articles on this site and others.

After that deluge of information I spent about 4 hours last night trying various techniques. I strapped a microphone to the door and tried listening, but either that isn't effective in this case, or I can't properly detect the sound signature. After that I tried measuring handle deflection. I knew the last number so, using the National Locksmith's article, I ghetto rigged an indicator, mini clamped it to the handle and slapped an index marker on the top of the door. This also got me next to nothing. I don't know if it was the rubber bands not applying the correct handle pressure, not being able to detect the subtle movements well enough, the plastic handle allowing too much give, or possibly just a complete misunderstanding of the whole process on my part.

At this point. I'm thinking about just brute forcing it. Almost every Sentry fire safe combination I've seen (whether it be from posts here, reviews, or official sentry videos) show a combo that is fairly evenly spaced (30-60 away from either other number). Since the assumption is that no two numbers can lie on the same 1/3 of the dial (give or take), that leaves me with about 2200 possible combinations. However, it also seems like these cheap fire safes have a tolerance of about 2 or so. So that cuts the possible combinations in half. 1100 +/- a couple hundred is still a chore, but not something that can't be done. I have no time limit, so I can just spend an hour or so a night slowly working my way through until I potentially get it.

However, since I found the earlier failed attempts oddly enjoyable, I am probably going to continue learning and practicing. Despite reading countless articles and watching too many videos, I realize that I need a better way to understand and more importantly visualize exactly what I'm doing when I interact with the lock. I've priced a few cutaways for practice, but if I get this safe open, I could just use it for awhile. I have no other use for it.

Until then, are there any somewhat detailed software solutions for practicing? Something I could launch of my computer and tinker with to try and get a firmer grasp on exactly what is happening.
Any other advice?

I apologize if anything in this post is ignorant beyond belief. I'm sure I've made some incredible mistakes in multiple places.

Thanks for the help.


One last thing. My sister is insistent that after closing the door, turning the dial right from 35, past 0, and to about 70 would allow for the safe to be opened again by simply turning it back left to 35. Anything beyond 70 and it wouldn't work. I'm not 100% sure if that's accurate or what it means, but 70 lies in the range I was brute forcing anyway so I somewhat ignored it. For referench the safe is a R-L-R combo.

Re: Beginner with a Sentry. The story of zero progression.

PostPosted: Sat Sep 23, 2017 12:48 pm
by Traviality
Wow.........so apparently writing this up allowed me to sift through and organize the information I had. I threw in the last paragraph in this post without really thinking about it. It was just a random bit of info. After posting though, I thought about it and decided to start brute forcing with the second number from 65-75.

After only 20 minutes, it's open. 02-69-35. Evenly spaced and each one lies on a different third of the dial. Technically 35 and 2 are on the same one, but it's very close and I was going to brute force slightly above and below 33.33 away anyway.

I know I didn't really succeed in manipulating this, but I am a little proud for getting this open with just pure logic and a bit of math. Yes knowing one of the numbers helped, but it's fairly easy to find that number on this safe anyway. When testing false gates I found that with the handle down the dial would only turn +/- 1 spot. So 2. Going to 35 however allowed it to move +/-2. So 4. It was almost 5. Which helped confirm that the known number was actually correct.

Maybe I got lucky and all of the assumptions I made were complete bullshit. I know I got a little lucky with the first number being 02. I started at 0 and was trying second numbers from 65-75. It could have taken a bit longer. However, since I was just testing 65-75 for the second number, and I knew the last number was 35, I was assuming that the first would be between either in the 90s or low 00s or 10s. It started at 0 instead of 90 purely due to 0's inherent appeal as a starting place. So luck was definitely a factor, and maybe if I went and bought another of this exact model my slightly large leaps to conclusions would fail.

Now I'm off to take the back off the door and see how close I actually was to the real combo and then I'll spend some time fiddling to see what I was doing wrong in the beginning.

Re: Beginner with a Sentry. The story of zero progression.

PostPosted: Sun Sep 24, 2017 10:15 pm
by Oldfast
Nice job! You explored what clues you had... and it panned out.

Traviality wrote:Now I'm off to take the back off the door.....

Damn right. Now it's time to learn. Gather all the specs you can
from it. And you'll be that much more equipped for the next one.

Exciting stuff! Welcome to the forum.

Traviality wrote:Until then, are there any somewhat detailed software solutions for practicing? Something I could launch of my computer and tinker with to try and get a firmer grasp on exactly what is happening.

None that I'm aware of.

Traviality wrote:Any other advice?

Not really. All the literature you've found already is a great start.
Also, Femurat has a nice article for beginners. Search his posts.
Other than that, I'd say just get you're hands on some more locks.