public void GetModificationTimeTest() { // Arrange byte[] derivedKey = new byte[16] { 15, 200, 3, 4, 15, 6, 7, 8, 9, 10, 11, 112, 139, 104, 15, 16 }; byte[] initialCounter = new byte[] { 0xf0, 0xf1, 0xfb, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xf3, 0xff }; SettingsAES_CTR settingsAES_CTR = new SettingsAES_CTR(initialCounter); SymmetricKeyAlgorithm skaAES_CTR = new SymmetricKeyAlgorithm(SymmetricEncryptionAlgorithm.AES_CTR, 128, settingsAES_CTR); PaymentCard paymentCard = new PaymentCard("Bank of Dragon", "Cool Dragon", "Debit", "0000000000001234", "111", "11/20", "05/33", "Super cool card I have here"); PaymentCardSecret paymentCardSecret = new PaymentCardSecret(paymentCard, "does not matter", skaAES_CTR, derivedKey); // Act DateTimeOffset modificationTime1 = paymentCardSecret.GetModificationTime(derivedKey); Thread.Sleep(1100); paymentCardSecret.SetTitle("1234567", derivedKey); DateTimeOffset modificationTime2 = paymentCardSecret.GetModificationTime(derivedKey); // Assert Assert.Greater(modificationTime2, modificationTime1); }