ECCPSignSM2 or GFpECSignSM2

[huang__zhongqiang]

There are two SM2 signature functions in ippcp which belong to different catagories. What is the difference between them?

Parent topic: Public Key Cryptography Functions

• Functions Based on GF(p)                                 <------------------- ECCPSignSM2
• Arithmetic of the Group of Elliptic Curve Points <------------ GFpECSignSM2

[Igor_A_Intel · Accepted solution]

Hi Zhongqiang,

Below is related information from IPP crypto expert:

Right, there are 2 implementations of EC functionality in IPP.

The 1-st, from historically point of view, there was ippsECCPxxx. This implementation assumes prime underlying Finite Field GF(p).

Later, IPP introduces another one – ippsGFpECxxx functionality. This implementation assumes prime underlying Field could be either prime (GF(p)) as extension of Finite Field (GF(p^n)) or even multi extension GF(p^n^m).

In any means, ippsGFpECxxx functionality is more general and flexible.

Why IPP did that? Some of our customers are using EC over extension of Finite Field.

What is the future of ippsECPxxx functionality? Believe it will be deprecated. So, it could be better to use ippsGFpECxxx functionality instead of old ippsECCPxx one.

Functions ECCPSignSM2 and GFpECSignSM2 are the same (at least in terms of result) if GFpECSM2 is using prime underlying Finite Field.

regards, Igor

[huang__zhongqiang]

Hi Igor,

Your answer is very helpful.

Also, is there SM2 encryption and decryption APIs (encrypt by public key and decrypt by private key) in ippcp? I only found SM2 signing and verification functions in ippcp, no SM2 encryption/decryption functions.

[Igor_A_Intel]

IPP doesn't provide such functionality. You can submit a feature request via official channel.

regards, Igor