Search

Identity-based proxy re-encryption (IB-PRE) is a kind of public key cryptography that allows a proxy to convert the ciphertext based on Alice's identity into another ciphertext of the same message for Bob. It has important applications in cloud computing, distributed systems and secure e-mail forwarding. So far, the existing lattice-based IB-PRE schemes are designed on the general lattice and their security is based on the learning with errors (LWE) assumption. In this paper, we propose an IB-PRE scheme over NTRU lattices with the desirable properties of anonymity, unidirectionality, backward collusion safeness and multi-hop. Our IB-PRE scheme is provable secure under adaptive chosen-plaintext and adaptive chosen-identity attacks. And, in the random oracle model, the security of our scheme is based on the decisional Ring-LWE assumption. Besides, the key and ciphertext sizes of our IB-PRE scheme are short, only one or two ring elements, and our scheme could encrypt n bits in each encryption process. [ABSTRACT FROM AUTHOR]

The era of the Internet of Things (IoT) has arrived and much information is transmitted through various small IoT devices. Public key cryptography can be used in the present internet environment to avoid eavesdropping. The well-known public key cryptography, Rivest–Shamir–Adleman cryptography and Elliptic Curve Cryptography are apt to be broken when quantum computing is introduced. Therefore, lattice-based cryptography has been proposed as a new public key cryptography to replace them. The Ring-LWE scheme has been proposed to implement lattice-based cryptography. To apply the scheme to IoT devices using 8-bit, 32-bit, or 64-bit microcontrollers, optimization is inevitable. Further, the 8-bit environment is more important for small IoT devices. However, Ring-LWE may be vulnerable to side-channel attacks. This paper analyzes the attack scenario and tenders a countermeasure through bit checking for IoT applications using 8-bit microcontrollers. [ABSTRACT FROM AUTHOR]