func testEncryptString(value:String){
        //Create a symmetricKey with the tag: "my.symmetric.key.tag"
        let symmetricKey = SymmetricKey(symmetricTagIdentifier: "my.symmetric.key.tag")
        
        //generates a new Symmetric Key
        symmetricKey.generateSymmetricKey()
        
        //creates a cipher for the text
        var cipher = Cipher(input: value, symmetricKey: symmetricKey)
        
        //encrypts the text
        let encrypted = cipher.encrypt()
        
        println("Encrypted result")
        prettyPrint(encrypted!)
        
        //creates a cipher for the encrypted text
        cipher = Cipher(input: encrypted!, symmetricKey: symmetricKey)
        
        //decrypts the text
        let decrypted = cipher.decrypt()
        
        //turn it into a string
        let decryptedStr = NSString(data: decrypted!, encoding:NSUTF8StringEncoding)
        
        println("Decrypted result")
        println(decryptedStr)
        
        let str = value as NSString
        //make sure they match
        XCTAssert(str == decryptedStr, "encrypted and decrypted values are equal")
    }

  func testEncryptImage() -> NSData {
        //load an image file
        let image = UIImage(named:"testImage.jpg")
        let imageData = UIImageJPEGRepresentation(image, 1)!
  
        //Create a symmetricKey with the tag: "my.symmetric.key.tag"
        let symmetricKey = SymmetricKey(symmetricTagIdentifier: "my.symmetric.key.tag")
        
        //generate the SymmetricKey .. since it is a new one
        symmetricKey.generateSymmetricKey()
        
        //creates a cipher for the image
        var cipher = Cipher(input: imageData, symmetricKey: symmetricKey)
        
        //encrypt the contents of the image
        let encrypted = cipher.encrypt()
        
        //an encryptedImage Image is useless ;-)
        let encryptedImage = UIImage(data:encrypted!)
        
        //creates a cipher for the encrypted image
        cipher = Cipher(input: encrypted, symmetricKey: symmetricKey)
        
        //decrypt the image
        let decrypted = cipher.decrypt()!
        
        //make sure the contento of the original is the same as the decrypted !
        XCTAssert(decrypted.isEqualToData(imageData!), "encrypted and decrypted images are equal")
        
        return decrypted
    }

    func testWrapAndUnwrapSymmetricKey(){
        //Create a keyPair object with these two tags
        let keyPair = KeyPair(privateTagIdentifier: "private.key", pulicTagIdentifier: "public.key")
        
        //generate a new Key Pair
        keyPair.generateKeyPair();
        
        let symmetricKey = SymmetricKey(symmetricTagIdentifier: "symmetric.key")
        //generate a new symmetricKey
        symmetricKey.generateSymmetricKey()
        
        println("symmetric key (plain): ")
        prettyPrint(symmetricKey.getSymmetricKeyBits()!)
        
        //wrap the symmetricKey with the public key
        let wrappedKey = symmetricKey.wrapSymmetricKey(keyPair.getPublicKeyRef()!)
        
        println("symmetric key (wrappedKey): ")
        prettyPrint(wrappedKey!)
        
        XCTAssert(wrappedKey != nil, "Has symmetricKeyRef")
        XCTAssert(wrappedKey?.length == 128, "Result the right size")
        
        //unwrap the symmetricKey using the privateKey
        let unwrappedKey = symmetricKey.unwrapSymmetricKey(keyPair.getPrivateKeyRef()!, wrappedSymmetricKey: wrappedKey!)
        
        println("symmetric key (unwrappedKey): ")
        prettyPrint(unwrappedKey!)
        
        //check if the unwrapped key is the same as the original value
        var boolCheck:Bool = false
        if let originalKey = symmetricKey.getSymmetricKeyBits() {
            boolCheck = originalKey.isEqualToData(unwrappedKey!)
        }
        XCTAssert(boolCheck, "wrappedKey and unwrappedKey are equal")
    }