Dear Researchers, I would like to know what are the security issues in block chain technology? thanq in advance
In first two generations of Blockchain, there may be no issue with security aspect. However, in third generation (e.g AION) it can occur. In first two generations, issues are related to power consumption and storage.
There are quite a few potential security issues and there is more and more literature on that subject. Here are a couple of examples:
*) Forks that can be caused by sybil nodes or selfish mining
*) 51% attacks: someone attains the majority in a network and abuses it
*) selfish mining: miners trying to increase their rewards by keeping blocks private
*) DNS attacks: sending peers wrong information
*) mempool attacks: flooding new blocks with transactions
*) DDos attacks: achieving denial of service
*) consensus delay: preventing peers from reaching consensus
*) double spending attacks: creating two transactions from the same unspent transaction
*) Theft of wallets
I suggest that you check the March 2018 issue (volume 6) of the IEEE Access (open) Journal, which has a specific topic on: " Research Challenges and Opportunities in Security and Privacy of Blockchain Technologies ". There are around 17 articles.
link:
https://ieeexplore.ieee.org/xpl/topics.jsp?filter=issueId%20EQ%20%228274985%22&refinements=SpecialSection:Research%20Challenges%20and%20Opportunities%20in%20Security%20and%20Privacy%20of%20Blockchain%20Technologies&pageNumber=1&resultAction=REFINE
https://due.com/blog/issues-blockchain-security/
https://igniteoutsourcing.com/publications/blockchain-security-vulnerabilities-risks/
https://www.coindesk.com/information/blockchains-issues-limitations/
Article Blockchain technology for security issues and challenges in IoT
On top of the security issues mentioned by Horst Treiblmaier , there are issues around safeguarding private keys. Furthermore, securing the link between the blockchain infrastructure and the peripheral applications that are reading and writing from and to the blockchain is not to be ignored! In other words, protecting a blockchain-based solution is not limited to the blockchain structure only, but should also consider the whole chain of requests/responses to eliminate risks of man-in-the-middle (MITM) attacks. This is much harder than it can be thought!
Check out this article. It summarises the top 5 blockchain security issues in 2019.
https://lifars.com/2019/12/top-5-blockchain-security-issues-in-2019/
The articles on this site might be helpful
https://101blockchains.com/blockchain-security-issues/