A Digital Signature Scheme Based on MST₃ Cryptosystems

Table 1

Number of basic operations for one encryption/decryption.

		𝔽2^𝑚 ADD	𝔽2^𝑚 MULT	𝔽2^𝑚 EXP(𝜃)	𝔽2^𝑚 PRNG	Factor
Encryption^1	𝑒𝑀𝑆𝑇3 scheme [34]	8𝑠−6	2𝑠−2	—	1	—
	Our scheme	8𝑠−7	2𝑠−2	—	1	—
Decryption^2	𝑒𝑀𝑆𝑇3 scheme	4𝑠+15	𝑠+5	1	—	1
	Our scheme	4𝑠+10	𝑠+3	—	—	1

1Compared with 𝑒𝑀𝑆𝑇₃ scheme, our scheme reduces a step of multiplication with the element of the center 𝒵 in the stage of encryption. Thus, the number of (𝔽₂^𝑚 ADD) reduces once.
2In the stage of decryption, our scheme reduces a step of inverse operation, a step of multiplication operation, and a 𝔽₂^𝑚 EXP(𝜃) operation, so the number of (𝔽₂^𝑚 ADD) reduces five times and (𝔽₂^𝑚 MULT) reduces twice.