Further improvement of public key encryption algorithm using RSA

Creating a software application requires asymmetric encryption.AlgorithmEncryption of registration information. What I did not expect was that RSA could only use the public key to encrypt and decrypt the private key. This is exactly the opposite of my needs. So I found the encryption algorithm developed by Niu Ren on the Internet, after use, you can find that there is a problem with Chinese support.

Address: http://www.cnblogs.com/hhh/archive/2011/06/03/2070692.html

The original algorithm splits the input string by 128 characters in each segment. However, if there is a Chinese character in the split position, garbled characters may occur after decryption, which is a headache.

After studying the algorithm carefully, I found that the method for processing data in the string method was not reasonable, so I overwrote the algorithm and processed it in binary mode, successfully solving the garbled problem, the following are the improved algorithms.

         Public   Static   Byte [] Encrypt ( Byte  [] Data, biginteger D, biginteger N ){  Int Size = 128  ; Byte [] Buffer = New   Byte  [Size];  Using (Memorystream source = New  Memorystream (data ))  Using (Memorystream output = New  Memorystream ()){  Int  Bytes;  While (Bytes = source. Read (buffer,0 , Size)> 0  ) {Biginteger bi1 = New  Biginteger (buffer, bytes); biginteger bi2 = Bi1.modpow (d, n); Data = Bi2.getbytes (); system. Diagnostics. Debug. Assert (data. Length < 256  ); Output. writebyte ((  Byte  ) Data. Length); output. Write (data, 0  , Data. Length );}  Return  Output. toarray ();}}  Public   Static   Byte [] Decrypt ( Byte  [] Data, biginteger E, biginteger N ){  Using (Memorystream input = New  Memorystream (data ))  Using (Memorystream output =New  Memorystream ()){  Int  Length;  While (Length = input. readbyte ()> = 0  ){  Byte [] Buffer = New   Byte  [Length];  If (Input. Read (buffer, 0 , Length )! =Length)  Throw   New  Invaliddataexception (); biginteger bi1 = New  Biginteger (buffer); biginteger bi2 = Bi1.modpow (E, n); Buffer = Bi2.getbytes (); output. Write (buffer,  0  , Buffer. Length );}  Return Output. toarray ();}}  Public   Static   String Encrypt ( String Source, String D, String  N ){  Byte [] N = Convert. frombase64string (N );  Byte [] D = Convert. frombase64string (d); biginteger Bin =New  Biginteger (n); biginteger bid = New  Biginteger (d );  Byte [] DATA = System. Text. encoding. utf8.getbytes (source); Data = Encrypt (data, bid, BIN );  Return  Convert. tobase64string (data );}  Public   Static   String Decrypt ( String Source, String E, String  N ){  Byte [] N = Convert. frombase64string (N );  Byte [] E = Convert. frombase64string (E); biginteger Bin = New  Biginteger (n); biginteger BIE = New  Biginteger (E );              Byte [] DATA =Convert. frombase64string (source); Data = Decrypt (data, Bie, BIN );  Return  System. Text. encoding. utf8.getstring (data );} 

Finally, I would like to thank the author for his efforts and saved me many things.

ReferenceArticle:

[1]RSA private key encryption and Public Key decryption algorithm

[2] C # Improve public key encryption and decryption using RSA private key to solve the problem of garbled code after decryption in specific circumstances

[3]Biginteger big Integer Operation class