Original:"Encrypt" File Another Method ------ A Sneaky Usage of the expand Command - China DOS Union Forum

The expand command is used to expand one or more compressed files. For the specific usage, please look at expand /?

Everyone, try executing the following command under cmd: cd c:\ &>a.txt echo test &expand a.txt b.txt:bb &del a.txt

Now go to c:\ and see, there is an additional b.txt, and then it is found to be an empty file. The a.txt just now was obviously not an empty file. Why is it expanded to b.txt as an empty file? That's strange! Hehe

Okay, now to restore a.txt, execute: cd c:\ &expand b.txt:bb a.txt

Now see, isn't it restored again? The content of a.txt is exactly what we just wrote in with echo

Okay, now let's use this

We use it to "encrypt" files
Execute: expand source file target file:**, ** can be written randomly (I only tested writing letters). After encryption, delete the source file, so that others can't see the source file no matter what

When we need to "decrypt" the file
Execute: expand target file:** source file, just note that ** must be exactly the same as the ** used in "encryption", otherwise it can't be "decrypted"
Also, directly executing: expand target file source file is not okay

Hehe, is it easy to use? Is it practical? After testing, it can be used completely. Changing the name of the new file, copying the new file to other paths, restarting the system, etc., have no impact

Question: Why is it an empty file? How can it be restored with an empty file? I don't understand, hope the experts can explain
Everyone, come and discuss~

[ Last edited by he200377 on 2006-9-26 at 08:00 ]

Floor1　vkill	Posted 2006-09-26 07:54
金牌会员　Posts 1,744　Credits 4,103　From 甘肃.临泽
The expand command is used to expand one or more compressed files. For the specific usage, please look at expand /? Everyone, try executing the following command under cmd: cd c:\ &>a.txt echo test &expand a.txt b.txt:bb &del a.txt Now go to c:\ and see, there is an additional b.txt, and then it is found to be an empty file. The a.txt just now was obviously not an empty file. Why is it expanded to b.txt as an empty file? That's strange! Hehe Okay, now to restore a.txt, execute: cd c:\ &expand b.txt:bb a.txt Now see, isn't it restored again? The content of a.txt is exactly what we just wrote in with echo Okay, now let's use this We use it to "encrypt" files Execute: expand source file target file:, can be written randomly (I only tested writing letters). After encryption, delete the source file, so that others can't see the source file no matter what When we need to "decrypt" the file Execute: expand target file: source file, just note that must be exactly the same as the ** used in "encryption", otherwise it can't be "decrypted" Also, directly executing: expand target file source file is not okay Hehe, is it easy to use? Is it practical? After testing, it can be used completely. Changing the name of the new file, copying the new file to other paths, restarting the system, etc., have no impact Question: Why is it an empty file? How can it be restored with an empty file? I don't understand, hope the experts can explain Everyone, come and discuss~ [ Last edited by he200377 on 2006-9-26 at 08:00 ]

Floor2　vkill	Posted 2006-09-26 07:55
金牌会员　Posts 1,744　Credits 4,103　From 甘肃.临泽
Just can't create folders, no matter how I try, it's frustrating

Floor3　electronixtar	Posted 2006-09-26 07:59
铂金会员　Posts 2,672　Credits 7,493
http://www.cn-dos.net/forum/viewthread.php?tid=21480&fpage=2 Need to top after reading the post

Floor4　vkill	Posted 2006-09-26 08:03
金牌会员　Posts 1,744　Credits 4,103　From 甘肃.临泽
The upstairs is saying it's NTFS streams, I didn't read your that post oh, just went in and looked and was also confused