PATENTS

from libressl source readme:

 PATENTS
 -------

 Various companies hold various patents for various algorithms in various
 locations around the world. _YOU_ are responsible for ensuring that your use
 of any algorithms is legal by checking if there are any patents in your
 country.  The file contains some of the patents that we know about or are
 rumored to exist. This is not a definitive list.

 RSA Security holds software patents on the RC5 algorithm.  If you
 intend to use this cipher, you must contact RSA Security for
 licensing conditions. Their web page is http://www.rsasecurity.com/.

 RC4 is a trademark of RSA Security, so use of this label should perhaps
 only be used with RSA Security's permission.

 The IDEA algorithm is patented by Ascom in Austria, France, Germany, Italy,
 Japan, the Netherlands, Spain, Sweden, Switzerland, UK and the USA.  They
 should be contacted if that algorithm is to be used; their web page is
 http://www.ascom.ch/.

 NTT and Mitsubishi have patents and pending patents on the Camellia
 algorithm, but allow use at no charge without requiring an explicit
 licensing agreement: http://info.isl.ntt.co.jp/crypt/eng/info/chiteki.html