Encrypt/Decrypt a piece of data with Key and IV using Apple's CommonCryptor (AES128)
Usage:
Encryption:
NSString *encryptedBase64String = [[ERCrypt alloc] AESEncrypt:sampleString iv:iv key:key];
Decryption:
NSString *decryptedBase64String = [[ERCrypt alloc] AESDecrypt:sampleString iv:iv key:key];