Today, the public key cryptosystem is widely used in the computer-based information security.
The system, however, has the disadvantage of serious asymmetry between encryption and decryption speed.
A lot of experts have made painstaking efforts to solve this problem.
Kim Kyu Chol (pictured), researcher at the information science and technology faculty of Kim Chaek University of Technology, published a relevant SCI-class paper of great significance last year.
“My research goal is to balance encryption and decryption in the public key cryptosystem with the help of a convenient method,” he said.
In his paper “Fast rebalanced RSA signature scheme with typical prime generation”, he demonstrated that already-used typical prime generation can be used in the fast rebalanced RSA signature.
RSA has attracted the interest of many mathematicians and cryptographers since the initial days of its development as the first public key cryptogram with both the signature and encryption functions and it is still the research objects of many at present.
The preceding methods studied to increase the RSA signature speed had shortcomings as the standardized fast prime generation could not be used and it was hard to apply it to practice.
Kim Kyu Chol proposed the fast decryption in rebalanced RSA signature while reducing the CRT exponents maintaining the full sized private exponent for encryption and decryption with composite modulus and using typical prime generation as it was, and proved its security mathematically.
His research finding paved the way for practically introducing fast RSA signature method that had been in a discussion stage.
In “Research for increasing the speed of decryption in the ElGamal public key cryptogram with composite number as a module”, he provided a scientific and theoretical basis to settle the problem of simultaneous fast encryption and decryption in the field of public key cryptogram.
He proved that it is possible to ensure the encryption and decryption speed in the way of reducing the CRT secret exponents while maintaining the size of secret exponents including rebalanced RSA in the fast decryption of ElFamal cryptograph with composite modulus.
His papers were published in Theoretical Computer Science and PLOS One (Public Library Of Science One).