java - encryption program -

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i need idea creatin encryption program can 1 help!? need create program in java or c++ need create logic encryption prog should automatically encrypt document n should decrypt if givien conditions such password fulfilled ! plz !

i agree fielding. in case want homework, think it's ok use xor encryption:

java sample code:

public string xorenc(int enckey, string toenc) {     /*         usage: str = xorenc(integer_key,string_to_encrypt);         created matthew shaffer (matt-shaffer.com)     */     int t=0;     string s1="";     string tog="";     if(enckey>0) {         while(t < toenc.length()) {             int a=toenc.charat(t);             int c=a ^ enckey;             char d=(char)c;             tog=tog+d;             t++;         }      }     return tog; } public string xorencstr(string enckey, string toenc) {     /*         usage: str = xorenc(string_key,string_to_encrypt);         created matthew shaffer (matt-shaffer.com)     */     int t=0;     int enckeyi=0;      while(t < enckey.length()) {         enckeyi+=enckey.charat(t);         t+=1;     }     return xorenc(enckeyi,toenc); }

you may want start decryption process if correct password entered, should somehow store hash of decryption password on encrypted file. example encrypted file may this:

[md5 hash of password][encrypted data]

then compare entered password hash 1 have saved, if they're identical start decryption process.


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