Verifikasi Tanda Tangan Elektronik dengan Teknik Otentikasi Berbasis Kriptografi Kunci Publik Sistem Menggunakan Algoritma Kriptografi Rivest-Shamir-Adleman

To suppress the spread of COVID-19, almost all countries have been locked down. Most activities become work from home (WFH) so that triggers an increase in online transactions. Online transactions in-volving critical information require an electronic signature (DS), which is an authentication and verification tool. A fast and accurate pro-cess of sender legitimacy, authenticity, and anti-disclaimer is a must. The procedures used to prove the authenticity of DS, authenticity of the signer’s identity, and anti-repudiation can be carried out with authentication techniques. The purpose of this study is to propose a DS verification with an authentication technique based on system public-key cryptosystems by reversing the role of the private key and public key in the Rivest-Shamir-Adleman cryptographic algorithm. The electronic information attached to the DS will be stored in the message M, using a hash function against M to produce h = H ( M ) . The value of h will be encrypted to be a DS with the private key PR ( d, n ) . The signature is verified to prove its authenticity by decrypting the DS using the public key PU ( e, n ) , thus obtaining the value of h. The value of h is compared with the value of h (cid:48) which is obtained from the value of the message hash function M of the examined DS. If h = h (cid:48) means the DS is authentic. If the digit size is d > e , the signing time is longer than the time required for verification, and vice versa.