Security Innovation NTRU cryptographic software invention and reference source code including NTRUCrypt and NTRUSign/PASS is a dual license product and includes open source and standard commercial licensing.
NTRU cryptographic IP and reference software may be used and modified to the needs of the user as long as the user adheres to version two (2) or higher of the GPL License. For details please refer to COPYING-2.txt included in this distribution.
The GPLv2 license may also be found on the gnu.org website at: (http://www.gnu.org/licenses/gpl-2.0.html)
The GPL licensing of NTRU is an irrevocable grant by Security Innovation, Inc. and cannot be withdrawn by Security Innovation, Inc, and/or any future owners of the Patented NTRU Algorithms.
This patent license applies to any program covered by this patent provided the program is released as specified above.
NTRU cryptographic IP used under the GPL may be included in other Free and Open Source Software (FOSS) products subject to the conditions in https://github.com/NTRUOpenSourceProject/ntru-crypto/blob/master/FOSS%20Exception.md
The grant of the ability to use NTRU under the GPL in other FOSS projects is an irrevocable grant by Security Innovation, Inc. and cannot be withdrawn by Security Innovation, Inc, and/or any future owners of the Patented NTRU Algorithms.
Parties who wish to distribute ntru-crypto, or components thereof, under licenses other than the GPL or the FOSS Exception must obtain a commercial license. Commercial licenses are available using flexible licensing terms on a one time per product fee or running royalty.
For details please ref The commercial license may also be found at the Security Innovation website (http://www.securityinnovation.com/NTRUlicense.doc)