Encrypt and decrypt string using c#

In this article, we are going to learn how to use the symmetric key for encrypting and decrypting data in C. Symmetric key is a string which is used to encrypt the data and with the same string, we can decrypt the data, which means a single string is required for encryption and decryption. Choose Console App.

In the above code, we used a predefined Aes class which is in System. Cryptography namespace that uses the same key for encryption and decryption. AES algorithm supports , , and bit encryption. We can also see in the above code that we used initialization vector IV which is of 16 bytes in size, the block size of the algorithm.

IV is optional. Improve this answer. Kolappan N 2, 2 2 gold badges 30 30 silver badges 36 36 bronze badges. Your comments about IV are incorrect, a 16 character UTF8 is 16 bytes, it works anyway because IV size is actually based on block size, not key size.

Also IV is being ascii decoded instead of utf8 decoded in decrypt. Ur answer talks about abstracting away salts and IVs but really u just removed them -- not modern or secure — jbtule.

This is unauthenticated encryption. An attacker can change the message without you being able to notice. He cannot learn the message but he can change it. CraigTP Good explanation but iterations is very low. When the PBKDF2 standard was written in , the recommended minimum number of iterations was , but the parameter is intended to be increased over time as CPU speeds increase. As of a Kerberos standard recommended iterations, Apple iOS 3 used , iOS 4 used , while in LastPass used iterations for JavaScript clients and iterations for server-side hashing.

Any chance for a. I am not allowed to answer the question, so I just comment here. As far as. NET Standard 2 goes, the block size must be Here's how it changes your code: github. Show 45 more comments. GetBytes 32 ; encryptor. CreateEncryptor , CryptoStreamMode. Write clearBytes, 0, clearBytes. Length ; cs. ToBase64String ms. CreateDecryptor , CryptoStreamMode. Write cipherBytes, 0, cipherBytes. GetString ms. A Ghazal A Ghazal 2, 1 1 gold badge 16 16 silver badges 11 11 bronze badges.

You probably shouldn't hard code the encryption key into the methods. This is very useful and simple for the numerous cases where we do not need the complexities of salt.

I just made the encryption key a parameter and was able to use the code successfully as is. FrenkyB to make the method portable, you can always pass the key as a method parameter. For example: public static string Encrypt string clearText, string encryptionKey This way you can have unique keys for each method call. My Code Analyzer warned that variable cs is being disposed twice.

We do not need redundant statements cs. Close in both Encrypt and Decrypt methods, since both will be disposed once control exists the using block. Show 7 more comments. CreateProtector Purpose ; return protector. Sergey Kolodiy Sergey Kolodiy 5, 1 1 gold badge 35 35 silver badges 57 57 bronze badges.

A quick note about the article you provided is that it states: " Encryption requires a key, which is created and managed by the data protection system. Keys are created with a default lifetime of 90 days, and stored in a suitable location according to the environment. Keys are temporary, so the data protection API is designed mainly for short term data protection scenarios ".

Just beware if you implement this method, that your keys expire after 90 days per default. PKCS7; this. CreateEncryptor symm. Key, symm. IV , CryptoStreamMode. Write data, 0, length ; cs. Close ; ms. ToBase64String Encrypt Encoding. CreateDecryptor symm. Read result, 0, result. GetString Decrypt Convert. FromBase64String data. DecryptString encr ;. John Alexiou John Alexiou IO; using System. Cryptography; using System. Write cipherText ; binaryWriter. ComputeHash encryptedStream.

ComputeHash encryptedMessage, 0, encryptedMessage. Length - sentTag. Copy encryptedMessage, encryptedMessage. Length, sentTag, 0, sentTag. Copy encryptedMessage, nonSecretPayloadLength, iv, 0, iv.

Length, encryptedMessage. Length - nonSecretPayloadLength - iv. IsNullOrWhiteSpace password password. Length]; Array. Copy nonSecretPayload, payload, nonSecretPayload. Copy salt, 0, payload, payloadIndex, salt.

Length ; Array. Length, authSalt, 0, authSalt. Text; using Org. Crypto; using Org. Engines; using Org. Generators; using Org. Modes; using Org. Parameters; using Org. NextBytes nonce, 0, nonce. GetOutputSize secretMessage. ProcessBytes secretMessage, 0, secretMessage. Length, cipherText, 0 ; cipher. ReadBytes encryptedMessage. Length - nonSecretPayloadLength - nonce.

GetOutputSize cipherText. ProcessBytes cipherText, 0, cipherText. Length, plainText, 0 ; cipher. NextBytes salt ; generator. Init PbeParametersGenerator. Pkcs5PasswordToBytes password. Copy salt,0, payload,nonSecretPayload. Length, salt. Length ; return SimpleEncrypt secretMessage, key.

Copy encryptedMessage, nonSecretPayloadLength, salt, 0, salt. Length ; generator. GetKey , salt. Here is an example using RSA. Encrypt System. GetBytes "Hello World!