To overcome this limitation, several so-called block cipher modes of operation have been designed[18][19] and specified in national recommendations such as NIST 800-38A[20] and BSI TR-02102[21] and international standards such asISO/IEC 10116.[22] The general concept is to use randomization of the plaintext data based on an additional input value, frequently called an initialization vector, to create what is termed probabilistic encryption.