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Bitcoin Cryptocurrency: Its Cryptographic Weaknesses and Remedies

  • Received : 2019.03.26
  • Accepted : 2019.10.04
  • Published : 2020.03.30

Abstract

Bitcoin (BTC) is a type of cryptocurrency that supports transaction/payment of virtual money between BTC users without the presence of a central authority or any third party like bank. It uses some cryptographic techniques namely public- and private-keys, digital signature and cryptographic-hash functions, and they are used for making secure transactions and maintaining distributed public ledger called blockchain. In BTC system, each transaction signed by sender is broadcasted over the P2P (Peer-to-Peer) Bitcoin network and a set of such transactions collected over a period is hashed together with the previous block/other values to form a block known as candidate block, where the first block known as genesis-block was created independently. Before a candidate block to be the part of existing blockchain (chaining of blocks), a computation-intensive hard problem needs to be solved. A number of miners try to solve it and a winner earns some BTCs as inspiration. The miners have high computing and hardware resources, and they play key roles in BTC for blockchain formation. This paper mainly analyses the underlying cryptographic techniques, identifies some weaknesses and proposes their enhancements. For these, two modifications of BTC are suggested ― (i) All BTC users must use digital certificates for their authentication and (ii) Winning miner must give signature on the compressed data of a block for authentication of public blocks/blockchain.

Keywords

References

  1. Andrychowicz, M., Dziembowski, S., Malinowski, D., and Mazurek, L. (2016). Secure multiparty computations on bitcoin. Comm. of the ACM, 59(4), 76-84.  https://doi.org/10.1145/2896386
  2. Back, A. (2002). Hashcash- A denial of service counter-measure. Retrieved from http://www.hashcash.org/papers/hashcash.pdf. 
  3. Badev, A., and Chen, M. (2014). Bitcoin: Technical background and data analysis. Finance and economics discussion series, divisions of research & statistics and monetary affairs, Federal Reserve Board, Washington, D.C. 
  4. Bergstra, J. A., and Weijland, P. W. (2014). Bitcoin: A money-like informational commodity. Retrieved from http://science.uva.nl/research/prog/publications. 
  5. Bitcoin - Wikipedia, Retrieved from http://en.bitcoin.it/wiki/Introduction 
  6. Dang, Q. H. (August, 2012). Recommendation for applications using approved hash algorithm. Publication 800-107 Revision 1, Technical report, National Institute of Standards and Technology (NIST). 
  7. European Central Bank, Virtual Currency Systems (October, 2012). ECB reports. Retrieved from http://www.ecb.europa.eu/pub/pdf/other/virtualcurrencieschemes201210en.pdf. 
  8. Garay, J., Kiayias, A., and Leonardos, N. (2015). The Bitcoin Backbone Protocol: Analysis and Applications. In: Oswald E., Fischlin M. (eds) Advances in Cryptology - EUROCRYPT 2015. EUROCRYPT 2015. Lecture Notes in Computer Science, vol 9057. Springer, Berlin, Heidelberg. 
  9. Johnson, D., Menezes, A., and Vanstone, S. (2001). The elliptic curve digital signature algorithm. International Journal of Information Systems, 1, 36-63. https://doi.org/10.1007/s102070100002 
  10. Karame, G., Androulaki, E., and Capkun, S. (2012). Two Bitcoins at the Price of One? Double-Spending Attacks on Fast Payments in Bitcoin. IACR Cryptology ePrint Archive, 2012(248). Retrieved from http://eprint.iacr.org/2012/248.pdf. 
  11. Kroll, J. A., Davey, I. C., and Felten, E. W. (2013). The economics of bitcoin mining, or bitcoin in the presence of adversaries. Proceedings of WEIS. 
  12. Lo, S., and Wang, J. C. (2014). Bitcoin as money? Federal Reserve Bank of Boston, Current Policy Perspective, No. 14-4. 
  13. Meiklejohn, S., Pomarole, M., Jordan, G., Levchenko, K., McCoy, D., Voelker, G. M., and Savage, S. (2013). A fistful of bitcoins: Characterizing payments among men with no names. Proceedings of the 2013 conference on Internet Measurement Conference. Retrieved from https://doi.org/10.1145/2504730.2504747 
  14. Merkle, R. C. (1988). A digital signature based on a conventional encryption function. In: Pomerance C. (eds) Advances in Cryptology - CRYPTO '87. CRYPTO 1987. Lecture Notes in Computer Science, vol 293. Springer, Berlin, Heidelberg. 
  15. Nakamoto, S. (2008). Bitcoin: A Peer-to-Peer electronic cash system. http://bitcoin.org/bitcoin.pdf. 
  16. Stallings, W. (2003). Cryptography and network security-principles and practices. Third Indian Reprint, Pearson Education.