encryption and decryption..

Question

hi..

i am developing a web application..

i want to store a number in table in encrypted format..

and also decrypt that encrypted value (stored in table)..

how to that..

i need coding in vb..
its a web application..

need ur suggestions..

thax
gopal

Ananth G · Answer

Encryption Sometimes we want to encrypt the values that time we use MD5 Encryption and Decryption Here i give the code for Encryption and Decryption. passPhrase ,saltValue ,initVector this variables are the key for Encryption and Decryption public static string passPhrase = "YOUR KEY1"; public static string saltValue = "YOUR KE2"; public static string initVector = "YOUR KE3"; public static string FunForEncrypt(string objText) { int keySize = 256; int passwordIterations = 03; string hashAlgorithm = "MD5"; byte[] initVectorBytes = Encoding.ASCII.GetBytes(initVector); byte[] saltValueBytes = Encoding.ASCII.GetBytes(saltValue); byte[] plainTextBytes = Encoding.UTF8.GetBytes(objText); PasswordDeriveBytes password = new PasswordDeriveBytes ( passPhrase, saltValueBytes, hashAlgorithm, passwordIterations ); byte[] keyBytes = password.GetBytes(keySize / 8); RijndaelManaged symmetricKey = new RijndaelManaged(); symmetricKey.Mode = CipherMode.CBC; ICryptoTransform encryptor = symmetricKey.CreateEncryptor ( keyBytes, initVectorBytes ); MemoryStream memoryStream = new MemoryStream(); CryptoStream cryptoStream = new CryptoStream ( memoryStream, encryptor, CryptoStreamMode.Write ); cryptoStream.Write(plainTextBytes, 0, plainTextBytes.Length); cryptoStream.FlushFinalBlock(); byte[] cipherTextBytes = memoryStream.ToArray(); memoryStream.Close(); cryptoStream.Close(); string cipherText = Convert.ToBase64String(cipherTextBytes); cipherText = HttpUtility.UrlEncode(cipherText); return cipherText; } Decryption : this below code used to Decrypt the text public static string FunForDecrypt(string cipherText) { string plainText = ""; int keySize = 256; int passwordIterations = 03; string hashAlgorithm = "MD5"; try { cipherText = HttpUtility.UrlDecode(cipherText); byte[] initVectorBytes = Encoding.ASCII.GetBytes(initVector); byte[] saltValueBytes = Encoding.ASCII.GetBytes(saltValue); byte[] cipherTextBytes = Convert.FromBase64String(cipherText); PasswordDeriveBytes password = new PasswordDeriveBytes ( passPhrase, saltValueBytes, hashAlgorithm, passwordIterations ); byte[] keyBytes = password.GetBytes(keySize / 8); RijndaelManaged symmetricKey = new RijndaelManaged(); symmetricKey.Mode = CipherMode.CBC; ICryptoTransform decryptor = symmetricKey.CreateDecryptor ( keyBytes, initVectorBytes ); MemoryStream memoryStream = new MemoryStream(cipherTextBytes); CryptoStream cryptoStream = new CryptoStream ( memoryStream, decryptor, CryptoStreamMode.Read ); byte[] plainTextBytes = new byte[cipherTextBytes.Length]; int decryptedByteCount = cryptoStream.Read ( plainTextBytes, 0, plainTextBytes.Length ); memoryStream.Close(); cryptoStream.Close(); plainText = Encoding.UTF8.GetString(plainTextBytes, 0, decryptedByteCount); } catch (Exception ex) { plainText = ""; } return plainText; }

Sneha Bawane · Answer

http://pankajtiwarii.blogspot.in/p/how-to-encrypt-or-decrypt-password.html See these article may be it eill helpful to u...

Vijaya Kadiyala · Answer

What is importance of the field? You can even think about encryption at the SQL Server level. http://windowsitpro.com/article/articleid/14035/how-do-i-encrypt-fields-in-sql-server.html Thanks -- Vijaya Kadiyala www.DotNetVJ.com

Johan Prinsloo · Answer

Do you want to use TDES, RSA or DES?