# what are the NTRU keysize and application in industry?

I'm a student currently working on a research project on the NTRU cryptosystem, I've read some papers about this cryptosystem, and in those papers they are talking about keysize, is it the size of the public key or private key ?

is there any other indusctrial application of NTRU apart from CyaSSL ?

• NTRU is patented, which has hampered adoption. – CodesInChaos Apr 20 '15 at 21:59
• security innovation announced in November 21, 2013 that NTRU is available for free use in open-source software the source code is available in this link – KamuiYato Apr 20 '15 at 23:16
• I think the question regarding the industrial application of NTRU is out of the scope of this site. – cygnusv Apr 21 '15 at 8:17

## 1 Answer

Usually, in public-key cryptography, the "key size" is implicitly referred to the size of the public key.

In the case of NTRU, both public and private keys are conveyed by the same thing: polynomials defined over a specific polynomial ring. These polynomials can be represented as vectors in $\mathbb Z_q$ of size $N$. Therefore, raw public and private key will have the same size ($N \cdot \lceil\log q\rceil$ bits). For instance, with $N = 1171$ and $q = 2048$, which are recommended parameters, public and private keys are of size 1.57 KB.

• please do you know any other industrial application of NTRU apart from CyaSSL ? – KamuiYato Apr 21 '15 at 10:13
• Check out this link. There is a section titled "Sample customers who’ve deployed NTRU". – cygnusv Apr 21 '15 at 10:39