Abstract
One of the modern directions in the field of information security is post-quantum cryptography. Its purpose is to develop new quantum-resistant cryptographic algorithms. An important section of post-quantum cryptography is electronic digital signature algorithms. There are a number of different approaches to designing post-quantum signatures. One of the main approaches to designing post-quantum cryptographic digital signature algorithms is hash-based post-quantum digital signature schemes. Hash-based post-quantum digital signature schemes are one of the main types of post-quantum cryptographic digital signature algorithms. They are quite efficient and provably secure. Their reliable security has been established against both classical and quantum attacks. There are many types of digital signatures for solving various information security problems, such as group signatures, ring signatures, blind signatures, verifiably encrypted signatures, etc. This paper proposes a new cryptographic protocol of verifiably encrypted signature with possibility of verification after a specified time based on the post-quantum cryptographic algorithm of hash-based digital signature, TANBA-SPHINCS+. The protocol is an efficient combination of the postquantum digital signature algorithm TANBA-SPHINCS+, the cryptographic protocol providing data encryption for a specified time, ECTLC, and the verifiably encrypted signature scheme.