// Generate an AES key for the purpose of this sample. 
// Normally this key should be stored in a protected //custom setting 
// or an encrypted field on a custom object
Blob cryptoKey = Crypto.generateAesKey(256);
 
// Generate the data to be encrypted.
 Blob data = Blob.valueOf('Test data to encrypted');
// Encrypt the data and have Salesforce.com generate the //initialization vector
Blob encryptedData = Crypto.encryptWithManagedIV('AES256', cryptoKey, data);
// Decrypt the data - the first 16 bytes contain the //initialization vector
 Blob decryptedData = Crypto.decryptWithManagedIV('AES256', cryptoKey, encryptedData);
 
// Decode the decrypted data for subsequent use
 String decryptedDataString = decryptedData.toString();

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