# Sign-Then-Encrypt Scheme with Cramer-Shoup Cryptosystem and Dissanayake Digital Signature

### Rahmad Bahri, Mohammad Budiman, Benny Nasution

#### 2023

#### Abstract

Exchanging information in the era of Internet-based technology still has security violations such as disclosure, modification, or destruction that make everyone worry about the exchange of information. The Dissanayake digital signature is part of asymmetric cryptography based on the factorization of prime numbers and has interesting mathematical properties. The property of such mathematics is that the sum of 2 odd numbers is a multiple of 4. The Dissanayake digital signature does not generate signatures directly through messages. The Cramer-Shoup algorithm is an asymmetric cryptographic algorithm that proved to be the first effective scheme to withstand Adaptive Chosen Ciphertext Attack (ACCA) attacks compared to existing cryptographic systems. The Cramer-Shoup algorithm is an extension algorithm of the Elgamal algorithm. This paper will implement a sign then-encrypt scheme using Dissanayake digital signature and Cramer-Shoup algorithm and analyze algorithms based on execution time and the avalanche effect. Based on simulation results, the charactersâ€™ length affects the execution time. The result of the process shows the length of the character linear with execution time. From the results of the avalanche effect simulation, Dissanayake digital signature got the average value of the avalanche effect of 51%, and the Cramer-Shoup algorithm got the average value of the avalanche effect of 49%. Implementing the sign-then-encrypt scheme can maintain security by encrypting and guaranteeing authenticity by adding a digital signature.

Download#### Paper Citation

#### in Harvard Style

Bahri R., Budiman M. and Nasution B. (2023). **Sign-Then-Encrypt Scheme with Cramer-Shoup Cryptosystem and Dissanayake Digital Signature**. In *Proceedings of the 3rd International Conference on Advanced Information Scientific Development - Volume 1: ICAISD*; ISBN 978-989-758-678-1, SciTePress, pages 131-138. DOI: 10.5220/0012444900003848

#### in Bibtex Style

@conference{icaisd23,

author={Rahmad Bahri and Mohammad Budiman and Benny Nasution},

title={Sign-Then-Encrypt Scheme with Cramer-Shoup Cryptosystem and Dissanayake Digital Signature},

booktitle={Proceedings of the 3rd International Conference on Advanced Information Scientific Development - Volume 1: ICAISD},

year={2023},

pages={131-138},

publisher={SciTePress},

organization={INSTICC},

doi={10.5220/0012444900003848},

isbn={978-989-758-678-1},

}

#### in EndNote Style

TY - CONF

JO - Proceedings of the 3rd International Conference on Advanced Information Scientific Development - Volume 1: ICAISD

TI - Sign-Then-Encrypt Scheme with Cramer-Shoup Cryptosystem and Dissanayake Digital Signature

SN - 978-989-758-678-1

AU - Bahri R.

AU - Budiman M.

AU - Nasution B.

PY - 2023

SP - 131

EP - 138

DO - 10.5220/0012444900003848

PB - SciTePress