In general, Triple DES with three independent keys (keying option 1) has a key length of 168 bits (three 56-bit DES keys), but due to the meet-in-the-middle attack, the effective security it provides is only 112 bits. Keying option 2 reduces the effective key size to 112 bits (because the third key is the same as the first). However, this option is susceptible to certain chosen-plaintext or known-plaintext attacks, and thus it is designated by NIST to have only 80 bits of security. This can be considered insecure, and, as consequence Triple DES has been deprecated by NIST in 2017.