Search found 17 matches

by AlexLiu
Tue Oct 16, 2018 5:40 am
Forum: Questions & Answers
Topic: how to get the available space of chip?
Replies: 4
Views: 715

Re: how to get the available space of chip?

but why the space size obtained by API is smaller than the actual space size?
by AlexLiu
Tue Oct 16, 2018 2:09 am
Forum: Questions & Answers
Topic: how to get the available space of chip?
Replies: 4
Views: 715

how to get the available space of chip?

how to get the available space of chip?
by AlexLiu
Tue Sep 18, 2018 5:29 am
Forum: Algorithm School
Topic: About the random number generation tool
Replies: 4
Views: 1522

Re: About the random number generation tool

RANDOM.ORG offers true random numbers to anyone on the Internet. The randomness comes from atmospheric noise, which for many purposes is better than the pseudo-random number algorithms typically used in computer programs. https://www.random.org/bytes/
by AlexLiu
Tue Sep 18, 2018 5:14 am
Forum: Questions & Answers
Topic: The range of ECC parameters N
Replies: 4
Views: 552

Re: The range of ECC parameters N

(1) verify if n is a prime, if not, then invalid; (2) check if n satisify the equation: h*n*G = o; if verify h*n*G = o is not easy, you can verify h*(n-1)*G = -G. here, usually h = 1, so the equation becomes: (n-1)*G = -G, the left of the equation, is a kG computation; about the right side, if G = (...
by AlexLiu
Tue Sep 18, 2018 5:04 am
Forum: Questions & Answers
Topic: Where to download the DES algorithm process standard document
Replies: 3
Views: 573

Re: Where to download the DES algorithm process standard document

this is the original DES specification: https://csrc.nist.gov/CSRC/media/Publications/fips/46/3/archive/1999-10-25/documents/fips46-3.pdf, but it was withdrawn on May 19, 2005, for related information, you can see: (1) Special Publication 800-131A, Transitions: Recommendations for Transitioning the ...
by AlexLiu
Tue Sep 18, 2018 4:29 am
Forum: Questions & Answers
Topic: How to set up SP800 random number test environment
Replies: 1
Views: 322

Re: How to set up SP800 random number test environment

1. Download the NIST Statistical Test Suite from the following website: https://csrc.nist.gov/CSRC/media/Projects/Random-Bit-Generation/documents/sts-2_1_2.zip 2. Download NIST documentation (available at http://csrc.nist.gov/publications/nistpubs/800-22-rev1a/SP800-22rev1a.pdf); 3. perform the step...
by AlexLiu
Tue Sep 18, 2018 4:11 am
Forum: Questions & Answers
Topic: SP800 random number test, where can the latest standards come down?
Replies: 2
Views: 378

Re: SP800 random number test, where can the latest standards come down?

https://csrc.nist.gov/publications/sp800
800-22 Rev. 1a A Statistical Test Suite for Random and Pseudorandom Number Generators for Cryptographic Applications
by AlexLiu
Tue Sep 18, 2018 2:38 am
Forum: Questions & Answers
Topic: A question of PKCS5
Replies: 2
Views: 421

Re: A question of PKCS5

(1) AES block size is not 32 bytes, it is 16 bytes;
(2) if the data is 16 bytes, you still need to pad 0x10 to the end until its length is 32bytes;
(3) you need to pad at any case, even if the length is times of block size.
by AlexLiu
Tue Sep 18, 2018 2:31 am
Forum: Questions & Answers
Topic: The range of ECC parameters N
Replies: 4
Views: 552

Re: The range of ECC parameters N

About parameter n, you need to know: (1) n is the order of base point G, it means n*G = o; (2) n is a prime factor of #E(Fq); #E(Fq) is the order of elliptic curve, it means the total number points on the curve. (3) h = #E(Fq)/n,h is the cofactor, at most case, h equals to one. So, usually, n is the...
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