Practical distributed secret key generation for delay tolerant networks

Abstract

Delay tolerant networks (DTNs) are resource-constrained dynamic networks where a continuous end-to-end connectivity is not always available. In such a challenging network, a fixed infrastructure may not be connected when a DTN is partitioned or the message delay in the network is large. Thus, the traditional public key infrastructure system and identity-based encryption (IBE) system are not suitable for DTNs because they rely on centralized infrastructures and require multiple round-trip interactions. To address this issue, we propose a distributed secret key generation system with self-certified identity (SCI-DKG) that does not require any private key generator and threshold cryptosystem. Initially, each node generates a private key and distributes an initial message including a self-certified identity and secret sharings to members in a DTN. Receivers independently authenticate the identity and extracts some encryption parameters corresponding to the identity from this initial message. We prove that SCI-DKG is chosen ciphertext secure in the standard model, and it can resist potential network attacks. Simulation results show that SCI-DKG has smaller delay and higher successful ratio of secret key generation compared with IBE and hierarchical IBE systems implemented in a DTN.The specification describes three security headers for different security services, in which the confidentiality header is used to encapsulate encrypted payload of a bundle. In this paper, we focus on the secret key generation in initializing security and skip the discussion about other security issues.So far, most DTNs security studies employ an identity-based encryption (IBE) system to generate secret keys for nodes because IBE simplifies public key certificate management and has higher security performance. In an IBE system, users choose an arbitrary string (identity) as their public key, such as an email address, and the corresponding private key is issued by a private key generator (PKG) through a secure channel. We argue that the IBE system is difficult to implement in a DTN because of characteristics of large delay and frequent interruption. The centralized PKG cannot be connected when a DTN is partitioned and resources are constrained. Additionally, the security of DTNs is affected if the PKG suffers from attacks, such as blackhole attack [10,11] and denialof-service attack [12]. Therefore, the reliability of the IBE system may be questionable in DTNs. Most importantly, a PKG must verify a user's identity before a private key is issued to the user, but it is impractical if the network is in an intermittent connectivity. Consider an example in which a user wants to join a DTN by using an identity strAlice@example.com. The PKG cannot verify that the user is really the owner of this email address when the email server is disconnected.Therefore, Farrell et al. [9] suggested to adopt a distributed private key generation (DKG) system instead of an IBE system in DTNs. Unfortunately, existing DKG systems require to use a threshold cryptosyst...

Cryptographic Key Management in Delay Tolerant Networks: A Survey

“…To improve security and counter network disruptions, they also propose a distributed way to store public key certificates and certificate revocation list (CRL). The authors in [32] recognise that both traditional PKI system and IBC schemes are not suitable for DTNs because they rely on centralised infrastructures and require multiple round-trip interactions. They propose a distributed secret key generation system with self-certified identity that does not require any PKG and threshold cryptosystem.…”

Increasing secret key capacity of OFDM systems: a geometric program approach

“…[1][2][3][4][5][6][7][8][9][10][11][12] Among these schemes, extracting secret keys from the characteristics of wireless channels, which makes it possible for one-time pad, becomes a hot issue. Traditional security protocols and algorithms mainly rely on cryptography, hash functions, and some other mathematical properties to support the security services.…”

“…Therefore, the interest in physical layer security schemes, which exploits the inherent physical properties of the wireless medium to complement or enhance the existing cryptosystems, is growing. [1][2][3][4][5][6][7][8][9][10][11][12] Among these schemes, extracting secret keys from the characteristics of wireless channels, which makes it possible for one-time pad, becomes a hot issue. So far, numerous research works have focused on extracting secret keys based on the received signal strength indication, 3,4 channel impulse response, 3,5-7 channel phase 8 and multipath relative-delay, 9 etc in various scenarios.…”

“…In addition, the broadcast nature of wireless medium makes the key distribution vulnerable to eavesdropping attacks. Therefore, the interest in physical layer security schemes, which exploits the inherent physical properties of the wireless medium to complement or enhance the existing cryptosystems, is growing . Among these schemes, extracting secret keys from the characteristics of wireless channels, which makes it possible for one‐time pad, becomes a hot issue.…”

Advances in parallel, distributed, embedded, and ubiquitous systems

“…Delay tolerant networks are resource‐constrained dynamic networks where a continuous end‐to‐end connectivity is not always available. In the sixth paper, ‘Practical Distributed Secret Key Generation for Delay Tolerant Networks’ , Xie and Wang propose a distributed secret key generation system with self‐certified identity (SCI‐DKG), which does not require any private key generator and threshold cryptosystem. They prove that SCI‐DKG is chosen ciphertext secure in the standard model, and it can resist potential network attacks.…”