C Generate Random Encryption Key
Generating Public/Private Keys In C# And.NET. How to generate public/private key in C#. Asymmetric cryptography also known as public-key encryption uses a public/private key pair to encrypt and decrypt data. In.NET, the RSACryptoServiceProvider and DSACryptoServiceProvider classes are used for asymmetric encryption. I want to generate AES encryption key to be sent to the the other party in order to communicate securely. In the beginning the two nodes will create a shared session key by using Deffie-Helman protocol, then one of them will genreate AES key and send it. Where do key generation algorithms take the randomness from? Ask Question Asked 2 years, 11. $begingroup$ I was just wondering, because in many encryption tools like Veracrypt or GnuPG you have to generate pseudo randomness with your mouse movement. Browse other questions tagged random-number-generator randomness key-generation or ask.
- Start studying Security+ Chapter 5 review questions. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Public key systems that generate random public keys that are different for each session are called. Public Key Exchange (PKE). Data Encryption Standard c. Triple Data Encryption Standard d.
- Jun 17, 2013 Encrypt, decrypt and generate a key in C# using AES256. encryption.cs. Encrypt, decrypt and generate a key in C# using AES256. encryption.cs. Skip to content. All gists Back to GitHub. Sign in Sign up Instantly share code, notes, and snippets. Haeky / encryption.
| #regionEncryption |
| /// <summary> |
| /// Generate a private key |
| /// From : www.chapleau.info/blog/2011/01/06/usingsimplestringkeywithaes256encryptioninc.html |
| /// </summary> |
| privatestaticstringGenerateKey(intiKeySize) |
| { |
| RijndaelManagedaesEncryption=newRijndaelManaged(); |
| aesEncryption.KeySize=iKeySize; |
| aesEncryption.BlockSize=128; |
| aesEncryption.Mode=CipherMode.CBC; |
| aesEncryption.Padding=PaddingMode.PKCS7; |
| aesEncryption.GenerateIV(); |
| stringivStr=Convert.ToBase64String(aesEncryption.IV); |
| aesEncryption.GenerateKey(); |
| stringkeyStr=Convert.ToBase64String(aesEncryption.Key); |
| stringcompleteKey=ivStr+','+keyStr; |
| returnConvert.ToBase64String(ASCIIEncoding.UTF8.GetBytes(completeKey)); |
| } |
| /// <summary> |
| /// Encrypt |
| /// From : www.chapleau.info/blog/2011/01/06/usingsimplestringkeywithaes256encryptioninc.html |
| /// </summary> |
| privatestaticstringEncrypt(stringiPlainStr, stringiCompleteEncodedKey, intiKeySize) |
| { |
| RijndaelManagedaesEncryption=newRijndaelManaged(); |
| aesEncryption.KeySize=iKeySize; |
| aesEncryption.BlockSize=128; |
| aesEncryption.Mode=CipherMode.CBC; |
| aesEncryption.Padding=PaddingMode.PKCS7; |
| aesEncryption.IV=Convert.FromBase64String(ASCIIEncoding.UTF8.GetString(Convert.FromBase64String(iCompleteEncodedKey)).Split(',')[0]); |
| aesEncryption.Key=Convert.FromBase64String(ASCIIEncoding.UTF8.GetString(Convert.FromBase64String(iCompleteEncodedKey)).Split(',')[1]); |
| byte[] plainText=ASCIIEncoding.UTF8.GetBytes(iPlainStr); |
| ICryptoTransformcrypto=aesEncryption.CreateEncryptor(); |
| byte[] cipherText=crypto.TransformFinalBlock(plainText, 0, plainText.Length); |
| returnConvert.ToBase64String(cipherText); |
| } |
| /// <summary> |
| /// Decrypt |
| /// From : www.chapleau.info/blog/2011/01/06/usingsimplestringkeywithaes256encryptioninc.html |
| /// </summary> |
| privatestaticstringDecrypt(stringiEncryptedText, stringiCompleteEncodedKey, intiKeySize) |
| { |
| RijndaelManagedaesEncryption=newRijndaelManaged(); |
| aesEncryption.KeySize=iKeySize; |
| aesEncryption.BlockSize=128; |
| aesEncryption.Mode=CipherMode.CBC; |
| aesEncryption.Padding=PaddingMode.PKCS7; |
| aesEncryption.IV=Convert.FromBase64String(ASCIIEncoding.UTF8.GetString(Convert.FromBase64String(iCompleteEncodedKey)).Split(',')[0]); |
| aesEncryption.Key=Convert.FromBase64String(ASCIIEncoding.UTF8.GetString(Convert.FromBase64String(iCompleteEncodedKey)).Split(',')[1]); |
| ICryptoTransformdecrypto=aesEncryption.CreateDecryptor(); |
| byte[] encryptedBytes=Convert.FromBase64CharArray(iEncryptedText.ToCharArray(), 0, iEncryptedText.Length); |
| returnASCIIEncoding.UTF8.GetString(decrypto.TransformFinalBlock(encryptedBytes, 0, encryptedBytes.Length)); |
| } |
| #endregion |
I created this small function just to practice C code. It's a simple random string generator. #include #include char.randstring(int length) static int. You can't simply re-generate a truly random key because a random process will not reliably generate the same output, ever. And yes, you use that same key for encryption and decryption assuming you are using a symmetric key encryption method.
commented Jun 6, 2014
hi fairly new to the cryptography... please suggest a resolution |
commented Oct 9, 2017 • edited
edited
How-to save -safely- the private key ? Windows registry ? in disk ? I use ASP.NET applications. Test your code |