It was not until 2011 that the first open-source implementation appeared, and in 2013, Security Innovation exempted open source projects from having to get a patent license, and released an NTRU reference implementation under the GPL v2.
直到2011年出现了第一个开源实现，在2013年，Security Innovation豁免了开源项目的专利授权要求，并以GPL v2协议释放了一份NTRU的参考实现。