Brute force decryption

Hi, I currently have a legacy application wrote in java and am trying to develop a new updated version of the application. The application relies on inputs from encrypted text files, the only thing is i dont know the type of encryption used in the old application. Is there any way i can go about determining the type of encryption and then brute forcing it? The company that developed the encryption package no longer exists so its obviously impossible to get anywhere that way?

"ḇ踿៤⵲郣懁黐্球變鎸䷍級庨苢ꎠ쵆聡赒쪝㧄Ń妊筦欢ὂ☜㍯힝㩙ᖏ鐮纨Ἰд㌛ꔆ趞搣權ᖂ멉᲋◫혟䨺娼䀚旳몒㐉Ⓟ溄抳齮咣肈౬虹蝽ⶬॴꂺꪛ䅿儊걧杭츶事谐ॷ鴞叭⣦╆잂꘮Ӯ纴褯쨄䍼䇿춆趡学쐪益难뢺ྡྷ鲾꜡໚헼䞚犲㬳໤࿓쨜᝴搘᪰绠䯆龪䜋록蛇䵃砬럲弓ِἚᡰꔽ直迢绐䞚ꆅ黇출苅蕹Ϟ铀蜗鎅撑ጝ䝆윯뚕踁⺈ϧ徲ͪ⮛ᡀ녃ꎷⳡ呿瓘⾟졦킾⫧ꔊਘ똽뎟뢱ᴰᾍ娌ↀ캖毅咻횧⹔発Ὗ噧鶁籪柍㶠ꍈኬ௽钎ꖉ෢䬷Ↄ鴾俑乴" Heres a preview to the encrypted code, the length of each file changes and the symbols/characters used also differ? Any suggestions are much appreciated.

#TG

What's the extension? (This may tell you.)
Can you see what is in the header of the file? (The first few characters may tell you.)

.raw
nope i know what the unencrypted files look like but that doesnt help with the decrpytion surely?

[gusano79]

i know what the unencrypted files look like but that doesnt help with the decrpytion surely?

If the file contains encrypted data only, then you're right. However, the program that saved the file may have included other information with the encrypted data for some reason. It's worth looking at.

hmm okay, is it worth generating a few files and comparing them, or is it impossible to reverse engineer AES on a small timescale? I've decompiled the java but can't see anything relating to an encryption key. To encrypt the files a "Developer" dongle must be plugged into the machine that the program is ran from, i may see if i can access the contents of that dongle