Great puzzle. I laughed when I thought a "solution" could be to just try all backup keys as there are 100 tries. =D
My solution with one EXA (no SWIZ) - 579/45/4

MAKE
@REP 4
COPY 0 F
@END
LINK 800

MARK CODE
COPY #OUTP X

SEEK -9999
@REP 4
COPY F #PASS
@END

@REP 4
TEST #OUTP = X
TJMP DIGIT@{0,1}
@END

WIPE
LINK 800
GRAB 267
LINK -1
LINK -1
HALT

@REP 4
MARK DIGIT@{0,1}
COPY @{-4,1} X
JUMP INCREASE
@END

MARK INCREASE
SEEK X
COPY F X
SEEK -1
ADDI X 1 F
JUMP CODE

The discovery process was really satisfying, really sold the hacking vibe.

⣿⣿⣿⣿⠏⠌⣾⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿
⣿⣿⣿⣿⠀⠀⠸⠿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿
⣿⣿⣿⠃⠀⣠⣾⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿
⣿⡿⠃⠀⢰⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿
⣿⠃⠀⠀⣾⣿⣿⣿⣿⣿⣦⠀⠈⠻⣿⣿⣿⣿
⣿⠀⠀⠀⣿⣿⣿⠟⠉⠉⠉⢃⣤⠀⠈⢿⣿⣿
⣿⠀⠀⠀⢸⣿⡟⠀⠀⠀⠀⢹⣿⣧⠀⠀⠙⣿
⣿⡆⠀⠀⠈⠻⡅⠀⠀⠀⠀⣸⣿⠿⠇⠀⠀⢸
⣿⣿⠀⠀⠀⠀⠀⠀⠀⠀⠔⠛⠁⠀⠀⠀⣠⣿
⣿⣿⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀⣴⣿⣿
⣿⣿⠃⠀⠀⠀⠀⠀⠀⠀⠀⠀⣠⣾⣿⣿⣿⣿
⣿⣿⡇⠀⠀⠀⠀⠀⠀⠀⠀⣠⣿⣿⣿⣿⣿⣿
⣿⣿⡇⠀⠀⠀⠀⠀⠀⠀⢰⣿⣿⣿⣿⣿⣿⣿
⣿⣿⣿⠀⠀⠀⠀⠀⠀⠀⢸⣿⣿⣿⣿⣿⣿⣿
⣿⣿⣿⠀⠀⠀⠀⠀⠀⠀⠘⣿⣿⣿⣿⣿⣿⣿
⣿⣿⠁⠀⠀⠀⠀⠀⠀⠀⠀⢹⣿⣿⣿⣿⣿⣿
⣿⠟⠀⠀⠀⠀⠀⠀⠀⠀⠀⢠⣿⣿⣿⣿⣿⣿
⡟⠁⠀⠀⠀⠀⠀⠀⠀⠀⠀⢸⣿⣿⣿⣿⣿⣿

EDIT TO THE PREVIOUS COMMENT:
The
COPY F #PASS
COPY F #PASS
COPY F #PASS
COPY F #PASS
on ENTER is not needed, I didn't thought that the last try have to be correct, therefore, it will be opened :)

I finally did it. It's not well optimised but it only uses one EXA.
Here is my solution:

LINK 800
MAKE

;0: ADD VALUE
COPY 1000 F

;1: RESULT POINTER
COPY 2 F

;2: SWIZ POINTER
COPY 4 F

;3: WAIT WORD
COPY #OUTP F

MARK LOOP
SWIZ X 4 #PASS
SWIZ X 3 #PASS
SWIZ X 2 #PASS
SWIZ X 1 #PASS

COPY #OUTP F
NOOP
COPY #OUTP F
NOOP
COPY #OUTP F
NOOP
COPY #OUTP F
NOOP

SEEK -9999
SEEK 1
SEEK F

COPY F T
SEEK -9999
SEEK 3
TEST F = T
FJMP CORRECT

SEEK -9999
ADDI X F X
SEEK 3
JUMP LOOP

MARK RET
SEEK -9999
SEEK 1
TEST F = 6
TJMP ENTER
SEEK 2
JUMP LOOP

MARK CORRECT
SEEK -9999
SEEK 2
COPY F T
SEEK 9999
SWIZ X T F
SEEK -9999
DIVI F 10 T
SEEK -1
COPY T F
ADDI F 1 T
SEEK -1
COPY T F
SUBI F 1 T
SEEK -1
COPY T F
JUMP RET

MARK ENTER
SEEK 9999
SEEK -4
COPY F #PASS
COPY F #PASS
COPY F #PASS
COPY F #PASS

WIPE
LINK 800
GRAB 267
LINK -1
LINK -1
HALT

> Did this in 2021, neat stuff.
// Output: CHK CHK CHK CHK CHK CHK WAI WAI
// ERROR: Comment appears to contain incorrect number.

This has been the "trending" workshop item for several years. Congrats.

Very nice. I got it before reading any comments. But size was 512. I was happy enough just to come up with a solution.

Great puzzle. Messing with the inputs and figuring out what's going on is super satisfying.

Very nice puzzle, just showing my answer
405/32/5

LINK 800
MARK BRUTE
SWIZ X 4 #PASS
SWIZ X 3 #PASS
SWIZ X 2 #PASS
SWIZ X 1 #PASS
REPL CHECK
COPY X M
LINK 800
GRAB 267
LINK -1
KILL
LINK -1
MARK CHECK
COPY #OUTP X
TEST X = #OUTP
FJMP WRG2
TEST X = #OUTP
FJMP WRG3
TEST X = #OUTP
FJMP WRG4
ADDI 1000 M X
JUMP BRUTE
MARK WRG2
ADDI 100 M X
JUMP BRUTE
MARK WRG3
ADDI 10 M X
JUMP BRUTE
MARK WRG4
ADDI 1 M X
JUMP BRUTE

This is a really neat puzzle once you figure it out, though I do kind of wish there was an optional "supplemental material" like in the zines that would elucidate what exactly you're supposed to do -- It's weird, compared to the main game, going through it with absolutely no guidance.

Also, given the theme of the game, namely "leave no trace", I kind of wonder if it would be more in line to have you surreptitiously copy the file to a new file instead of stealing it outright... Still, I can see why this remains the top puzzle on the workshop.

Managed with 1 EXA out of necessity as communicating with another was too slow.
Hint: If only he had a pen and paper, then he wouldn't have to WAIt to CHecK with his friend.

very good puzzle!

Very clever. Other comments have said this but the exploration element is genius - feels like real-world hacking. Nicely done!

What this mean?We need to find out what all the answers have in common?

Finding the "flaw" in the system was actualy the most fun. Great hacking puzzle.

My Solution

LINK 800
MARK CODE
SWIZ X 0004 #PASS
SWIZ X 0003 #PASS
SWIZ X 0002 #PASS
REPL EXA_PROBE
SWIZ X 0001 #PASS
ADDI X M X
JUMP CODE

;=======================
;=======EXA_PROBE=======
;=======================
MARK EXA_PROBE
COPY #OUTP X
TEST #OUTP = X
TJMP FAIL_4
TEST #OUTP = X
TJMP FAIL_3
TEST #OUTP = X
TJMP FAIL_2
TEST #OUTP = X
TJMP FAIL_1
KILL
LINK 800
GRAB 267
LINK -1
LINK -1
HALT
MARK FAIL_4
COPY 1000 M ; 0 RIGHT
HALT
MARK FAIL_3
COPY 0100 M ; 1 RIGHT
HALT
MARK FAIL_2
COPY 0010 M ; 2 RIGHT
HALT
MARK FAIL_1
COPY 0001 M ; 3 RIGHT

That was a fun problem. I was able to get my solution down to 1 EXA with 36 lines of code.

This was a superb puzzle. Really gets into how actual hacking happens, which let's face it, is not always true in the main storyline puzzles. Great job!

I have working solution @ 404 cycles :(

reduced it from 4xx to 404 cycles by starting out from 0000 instead of 9999
but other than that I'm stumped ... can't optimize anymore.

losing a few cycles to having kill+wipe file 400 that was needed to store outp ... thinking maybe could do without the file but ended up making it less optimal

any hints?

Nice puzzle! I regret I've read comments before think about it for some time :)

BTW, I had nice idea to implement something similar in another problem that I was planning, but I was not able to fit solution in 100 lines - it could have fit in 150 lines, but I do not know of any way to increase allowed number of lines in workshop problems.

So, instead, I simplified problem to something that can fit in 100 lines, for a given definition of "simplify" - since it allow only 16 attempts ;p

https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=1511442342

I mentioned ZYZZY in description, since I got part of idea from this problem, but if author want me to remove it, please let me know.

I got a working solution. the only problem?
file size 103
fuck.

Nice one - I wonder if ZYZZY employees can open under 323 ;p

stumped... but i'm not going to read any comments until i figure it out :)

I enjoyed the shit out of this, especially the exploration element!

good one - was fun !

Finally got it. Great puzzle.

but... but... 10^4 > 100... Gulp.

@Ziboo: Try different keys (the correct one and some wrong alternations) and inspect the output.

Any hint ? I really don't get it...

This is genius, and I really appreciated the opportunity to do exploratory hacking and figure out what to do without being spoon-fed instructions.

Nice puzzle. Clever use of onCycleFinished.