Cryptographic Token Interface Standard

PKCS#11

ECDSA without hashing

The ECDSA without hashing mechanism, denoted CKM_ECDSA, is a mechanism for single-part signatures and verification for ECDSA. (This mechanism corresponds only to the part of ECDSA that processes the 20-byte hash value; it does not compute the hash value.)

For the purposes of this mechanism, an ECDSA signature is a 40-byte string, corresponding to the concatenation of the ECDSA values r and s, each represented most-significant byte first.

This mechanism does not have a parameter.

Constraints on key types and the length of data are summarized in the following table: 




 Table 66, ECDSA: Key And Data Length   
Function Key type 

Input length

 

Output length

   


C_Sign1 ECDSA private key 

20

 

40

   


C_Verify1 ECDSA public key 

20, 402

 

N/A

  

 



1 Single-part operations only.


2 Data length, signature length.


For this mechanism, the ulMinKeySize and ulMaxKeySize  fields of the CK_MECHANISM_INFO structure specify the minimum and maximum supported number of bits in the field sizes, respectively. For example, if a Cryptoki library supports only ECDSA using a field of characteristic 2 which has between 2200 and 2300 elements (inclusive), then ulMinKeySize = 201 and ulMaxKeySize = 301 (when written in binary notation, the number 2200 consists of a 1 bit followed by 200 0 bits. It is therefore a 201-bit number. Similarly, 2300 is a 301-bit number).


 
 



RSA Security Inc. Public-Key Cryptography Standards - 
PKCS#11 - v210