[BCP86]    Best Current Practice 86,
              <https://www.rfc-editor.org/info/bcp86>.
              At the time of writing, this BCP comprises the following:

              Orman, H. and P. Hoffman, "Determining Strengths For
              Public Keys Used For Exchanging Symmetric Keys", BCP 86,
              RFC 3766, DOI 10.17487/RFC3766, April 2004,
              <https://www.rfc-editor.org/info/rfc3766>.