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Blockchain contains a chain of blocks. Each block has a list of transactions, nonce value, time stamp, hash, and previous hash. Current block's previous hash value points the previous block's hash value.

Blockchain contains a chain of blocks. Each block has a list of transactions, nonce value, time stamp, hash, and previous hash. Current block's previous hash value points the previous block's hash value.

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Conference Paper
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Digital coin became an interesting subject for research in the last few years. For security reasons, the technical detail of digital coins (for example Bitcoin) are studied to stop security breaches. Bitcoin work dependently on a blockchain. Blockchain holds the record of all user’s transactions. The user opens a wallet with public/private key pair...

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Context 1
... extraction procedure is done with image processing procedure called Hough transform [21] as shown in Figure 10. Hough transform can be used to detect many geometric patterns in an image. ...
Context 2
... the security is moved from securing the data to securing the algorithm. Figure 11 shows an example of hiding the mnemonic "door ceiling casual grow issue reopen remind trouble among traffic liar exit" into fractal tree with 4 levels. Figure (a.1) is standard Stego-Fractal with L = 3 levels. ...
Context 3
... 11 shows an example of hiding the mnemonic "door ceiling casual grow issue reopen remind trouble among traffic liar exit" into fractal tree with 4 levels. Figure (a.1) is standard Stego-Fractal with L = 3 levels. Figure (a.2) is used to hide the mentioned mnemonic with 4 levels and small δ. ...

Citations

... Their scheme utilized the inferable defect of the ECDSA algorithm and combined the key variant with the blockchain transaction record to infer the original private key. Hosam [22] used steganalysis fractal techniques to hide key data in fractal tree graphics and made it more difficult for attackers to distinguish the implicit information. He et al. [14] put forward an encryption wallet scheme based on a semi-trusted social network. ...
Article
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Secure and stable cryptocurrency key management is important in modern cryptocurrency because the keys are the only way to access digital assets. Although many cryptocurrency wallet schemes have been proposed, some application limitations and inherent security risks still exist. In this paper, we propose a novel cryptocurrency wallet management scheme based on Decentralized Multi-Constrained Derangement (DMCD) to store the keys securely and stably in a decentralized network. Serving as the data distribution strategy, DMCD has high data dispersion and a better balance between the rate of storage space utilization and contribution, which can guarantee the security and stability of the key storage and recovery. In our scheme, to cope with the problem that nodes are frequently online and offline in the decentralized network, we employ a Shamir-Kademlia-Neighbor (SKN) redundancy strategy to ensure the high availability of stored key. Meanwhile, for achieving anonymous communication during DMCD data distribution, based on the Kademlia protocol, we change the Client/Server (C/S) mode of Hordes protocol to a decentralized version. All the proposed technologies can ensure that our scheme works well in a decentralized mode. The experiments and evaluations demonstrate that our scheme is efficient, stable, and secure in the decentralized network.
... Most owners' addresses, public keys and private keys (PriKeys) are stored in terminals locally, while few are stored in online wallet servers. Therefore, security of ownership is tightly related with PriKeys [8]. For instance, once a PriKey was breached by single point of failure, its ownership can be tampered illegally [5]. ...
... Major security threats about PriKeys include being lost by terminals, being breached by quantum computing attacks and being stolen of by online PriKey generators [6]. Some approaches are to prevent losing PriKeys by hiding them into specific indexes (such as hiding them into plain English text [7], fractal trees [8] and so on). Some approaches are to defend against quantum computing attacks by redesigning post-quantum blockchain schemes, which involve latticebased signature schemes [10], double-signature schemes [9] and anti-quantum transaction authentication schemes [11]. ...
... 2) Index-hidden Private Key Designs James Stanley proposed a stegoseed method by hiding PriKeys into plain English text [7]. Osama Hosam proposed a robust steganography technique, which hides PriKeys into fractal trees and discretizes angles and lengths of tree branches [8]. Nevertheless, nor plain text or fractal trees can prevent risks of losing by itself. ...
Article
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Traditional construction supply chains suffer from extra delays, costs and information wastages due to information intermediaries. Blockchain, a decentralized infrastructure, can provide irreversibility, undeniableness, uniqueness and anonymity for trades. Hence, we first propose a blockchain-based construction supply chain framework to reduce limitations in traditional ones. However, payment security by blockchain must be guaranteed and token assets in accounts must be protected. Although the loss of private keys will not result in the exposure or the modification of records in blockchain due to merkle root and blockheader hash, fake payments can be generated and all tokens in the accounts controlled by the private keys may be stolen by attackers. Existing approaches towards private-key protections include biometric-basic signature schemes, index-hidden private key designs and post-quantum blockchain schemes. Nevertheless, none of them can recover lost private keys. Therefore, we design a private-key distribution protocol in blockchains to preserve security of private keys with key recovery. Specifically, our scheme not only uses secret sharing to improve possibilities of recovering lost keys but also introduces network protocols to guarantee security of secret share transmission. The proposed scheme is then proven secure and feasible both in theoretical and experimental analysis.
Article
Full-text available
Bitcoin is a peer-to-peer electronic cash system largely used for online financial transactions. It gained popularity due to its anonymity, privacy, and comparatively low transaction cost. Its wallet heavily relies on Elliptic Curve Digital Signature Algorithm (ECDSA). Weaknesses in such algorithms can significantly affect the safety and the security of bitcoin wallets. In this paper, a secure key management wallet was designed based on several changes in the wallet parts. In the cold wallet, we employed an image-based passphrase to achieve a strong entropy source of master seed. The hot wallet, the proposed key_ Gen algorithm is modifying to the key generation step of the ECDSA that it is to generate a fresh key pair at each transaction. The final part ensures recovering all keys on both hot and cold wallets without daily backups in case of losing the wallet. The findings prove that the proposed cold wallet is resisting against a dictionary attack and overcoming the memorizing problem. The proposed hot wallet model acquires good anonymity and privacy for bitcoin users by eliminating transaction likability without additional cost. The execution time for signing a transaction of the proposed model is~70 millisecond, which is then important in the bitcoin domain