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Encrypting/hash algorithm challange; Question about finding out basic enchripting/hasing method based on encripted decripted pairs
Topic Started: Feb 21 2018, 10:21 PM (35 Views)
dalmode
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Hi there,

I have a legacy specialised machine (automated biochemistry analyser from the 80s) which use some onboard bottles with reagents marked with a barcode. When the machine is programmed, the text printed below the barcode is typed in the interface in order to link each kind of supply (reagent) with the assay in question.

The problem is that the printed text next to the barcode and the barcode value itself does not match - I believe there's some basic kind of encoding/encrypting between the two. The machine manufacturer is not existent since more than 20 years so there's no way to find original supplies with the barcodes or get any support or documentation. I managed to find 19 unique barcodes (and they all works fine) but I need more in order to obtain complete functionality. So I'm trying to find the encryption algorithm (based on what I have as encrypted decrypted pairs) in order to be able to create some more barcodes.

The barcodes are Code39 system with 4 characters in the barcode value and also 4 characters printed next to it. Here's what I have so far:
Encripted/decripted pairs
 

Printed text Barcode value
"AB1A" "- O-"
"AL1B" "-ULA"
"AM1C" "-W8H"
"AS1B" "..3A"
"BU1A" " X7K"
"CK1A" "$XC1"
"CL1B" "$ZZ8"
"DB1A" "/Z-B"
"DB2A" "/ZOT"
"FE1A" "B.19"
"FE2A" "B GK"
"FE4A" "B$GD"
"GT1C" "DNKX"
"TB1A" "WYZP"
"TB2A" "WZD7"
"TG1B" "X.DW"
"TP1A" "XQSP"
"UA1B" "YDO$"




So far I spent decent amount of time trying to find a solution. I have tried substituting each character with it's Code39 and/or ASCII numeric value and some basic arithmetical operations with the numeric values including modulus operations, ROT13, ROT47, Caesar shift. I've also tried some binary operations but nothing seems to work and I'm totally lost finding the logic here. I should say that I don't have experience in decrypting so far.

Any clues and/or suggestions that could help solving the puzzle are welcome and will be highly appreciated.

Thank you
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