The data of "precomp.c"

[ncepuzs]

Hello,
I am interested in the implementation of NTT in NewHope, but I don't understand the meaning of the data in "precomp.c" such as "psis_brv_montgomery". I thought the values in "psis_brv_montgomery" was computated as r^3j*2^18%12289 , where j is in bitrev_table and r=49. But I find i was wrong. Could you tell me how to get the four tables in "precomp.c"? I have been troubled for long time.
Thanks so much!

[tpoeppelmann]

Hi,

attached is the script that was used to generate the precomp.c:
ntt_precomputation.zip
Hope that makes it clearer.

Cheers
Thomas

[ncepuzs]

@tpoeppelmann Thanks very much! I have understood now.