Blockchain - Sicherheit auch ohne Trust Center

1. 00:00Let us draw a conclusion to our openHPI course "Blockchain: Security without Trustcenter".
2. 00:07What did we learn in our course?
3. 00:10We've introduced Blockchain, Blockchain, created in the context of the crypto currency Bitcoin, the basis for the security, trust model in a peer-to-peer network.
4. 00:24We looked at that, and about Bitcoin. this blockchain technology has also been very hyped and very widespread and loaded with great expectations.
5. 00:35The idea is that you can be in a trusted peer-to-peer network, where participants can join without control,
6. 00:43where we don't know the participants, the participants do not know each other,
7. 00:48where there is no trust between the participants, and yet these participants want something important. and trustworthy things like exchanging money,
8. 01:02So, this trust in this peer-to-peer network, how this can be done using blockchain, That's what we talked about.
9. 01:09And now specifically with the Bitcoins, that was the Nakamoto consensus.
10. 01:14We have seen how you can become a member of the Bitcoin network, which is a DNA seed like that.
11. 01:22We've seen how communications in the Bitcoin network, which is very similar to the way rumours spread.
12. 01:36We have seen that we have to change the order of the blocks via linked timestamps, can also define unverfaelschbar.
13. 01:46We have seen how the individual blocks are formed, as those created by miners in competition, where you can also earn something in the Bitcoin network.
14. 01:58We've seen how they try, by various means, that these miners are cheating.
15. 02:06One remedy was the proof of work, so that. before welding a lot of transactions into a block, one has to solve a very difficult cryptographic task
16. 02:19and answer the question, what is a hash value for which now, that the hash value then starts with a certain number of zeros,
17. 02:34something that can only be resolved by brute force.
18. 02:37Hard task also, the different miners that are there in the competition, it's not likely they'll be finished at the same time.
19. 02:44We have seen the principle of "longest chain wins" in the Bitcoin network, to prevent Sybil attacks and build trust.
20. 02:56We have learned further that there are also younger ideas, there are younger crypto currencies, Ethereum we have addressed.
21. 03:07Ethereum had this property, it was also blockchain-based, but it was possible with such an ethereum,
22. 03:15correctly write program code to the blockchain in a specially developed programming language,
23. 03:22which is then used by Ethereum Virtual Machines, which are located with the individual participants, can then be executed.
24. 03:30That was the idea of the Smart Contracts, which arouses a lot of imagination. for applications in very different areas.
25. 03:40We then also saw that for different applications it makes sense to think about different blockchain types.
26. 03:48Is Blockchain something new now?
27. 03:52Blockchain in the combination is something new.
28. 03:56Well, it's an ingenious combination. of existing approaches.
29. 04:02We've seen it in class, this thinking about peer-to-peer networks, where there's no master, no trust anchor,
30. 04:11that's been going on for a while, there's a lot of information on that already.
31. 04:15We've seen that in cryptography. Techniques with the Public Key Systems, where you can sign messages,
32. 04:24where each participant is given different keys, can assign a public, a private key, this has also been known for a long time.
33. 04:31We have seen that such consensus-building processes play a very central role in such peer-to-peer networks.
34. 04:40And to bring it all together cleverly, which has a monetary system, a monetary system. proved to be very appropriate Nakamoto consensus procedures,
35. 04:54this is the ingenious approach, this is Satoshi Nakamoto's merit, to have that put together into this blockchain technique, on which currency systems can then also run.
36. 05:11If we look at this blockchain technology, this technology, and reconsider the possibilities, then of course that's the idea,
37. 05:22that you can react autonomously in a network, without the need for a central location, without there being the bank that's costing us money.
38. 05:32This can therefore be organised autonomously and in a cost-saving manner, it's fail-safe, the bank's system is a single point of failure.
39. 05:41Here in a network like this, everyone has their own - for Bitcoin at least, for the design of the blockchain as for Bitcoin -
40. 05:50each of the participants has the full overview about all transactions, about all blocks.
41. 05:55Data integrity is ensured, counterfeit protection, traceability is ensured by the technology, that it is not possible afterwards, none of the participants is possible because something to manipulate.
42. 06:09The challenge and what makes it possible, where you also have to think about certain applications,
43. 06:17whether the use of the blockchain technique makes sense, of course a lot of computing power is needed.
44. 06:23So if you think of the Miner's mission in the Nakamoto Consensus and the calculation of this difficult cryptographic task,
45. 06:34storage capacities are needed, to save all the transactions first, then the blockchain, until they are then recognized in the blocks, in the blockchain.
46. 06:45We've also seen that it can't be done right away. for security reasons, but that a number of blocks must first be formed, before individual blocks belong to the block chain.
47. 06:57So one question is, what about the scalability? therefore ideas of at least a partial centralization are considered,
48. 07:07that was with the permissioned, with the allowed applications. that only certain participants in the network form blocks.
49. 07:16Issues of standards and interoperability, who, of course, are faced with such new technology, and the point is, the extent to which this is applied to certain areas of application.
50. 07:29All-rounders, if you follow the media and the many, many start-ups. and all the venture capital that's been put into such start-ups, if you take a look at the many projects of even the largest companies,
51. 07:43it looks like it's an all-rounder. with applications in all areas.
52. 07:49These different applications, that's when you think, is because such a public or private blockchain is the appropriate.
53. 07:58Blockchain can exist as blockchain-based products, Blockchain-based services.
54. 08:05Blockchain, if you look closely, is actually a base, a platform for specific applications.
55. 08:10Many start-ups, but also companies cooperate, to raise the potentials.
56. 08:19However, one will notice that in many areas of application the goal, what you want to achieve with such a blockchain solution, is also achieved with other possibilities.
57. 08:31In the area of open and original blockchain applications, in the area of Bitcoin, there is a very, very suitable infrastructure for such a monetary system.
58. 08:42But whether for an internal administration, where there are institutions anyway, which are given special trust,
59. 08:50there's a peer-to-peer technology. perhaps not applied so sensibly at all.
60. 08:57So now that you're thinking, how do I use this right? makes sense to use it in my context, in my company,
61. 09:05it makes sense to have an idea to start a start-up based on Blockchain, you should realize what your goal is.
62. 09:15When it comes to exchanging values, what is the application area? How is the benefit and effort of the use of the technology to be evaluated?
63. 09:23You have to offer to the opportunities and challenges, what if I want to use Blockchain?
64. 09:30Sure, then I have to give transparency, if I don't want to give this transparency at all for data protection reasons, how about the authorizations for updating.
65. 09:43If the few get it, how's that guaranteed? that they're doing this correctly.
66. 09:48You have to be clear about the cost-benefit ratio, blockchain already exists, or you set up a new blockchain.
67. 09:58And, of course, the implementation possibilities, that if a blockchain has only a small number of participants,
68. 10:07then this attack is when very much computing power in this network then lies with a participant or a group of participants,
69. 10:18then of course safety is no longer guaranteed, they can do a lot of things.
70. 10:22So when you see these consortia, these cooperations, who use Blockchain, then you can see how this will develop in the future, in which areas the blockchain is used permanently and sustainably.
71. 10:41Here are a few stories shown, large companies, Porsche, SAP, RWE, IBM, Microsoft, all are running projects, blockchain-based projects.
72. 10:55Some of these projects have been stopped, others have continued.
73. 11:00We have consortia, for example based on the use of Ethereum, the Ethereum Alliance, the Chain of Things, Hyperledger. R3 I had already displayed in a different context.
74. 11:16We have many start-ups based on blockchain technology. Applications (unv. #00:11:23-7# ), Blocks of Story, Slock.it, Consensys,
75. 11:28and so that's a question of how strong these consortia are, in order to keep the blockchain alive and to (unv. #00:11:40-7# )
76. 11:40So we're in this Gartner Hype Cycle. on the spot again, on this sloping area,
77. 11:46where now will crystallize out in the next few years, where the blockchain technology really does have sense and understanding and of great benefit.
78. 11:55Of course, we were only able to give the first introductions in these 14 days. into the topic blockchain.
79. 12:03We couldn't quite follow the techniques to the end.
80. 12:08In combination with the other courses, openHPI courses from our combined course to the Basic of Cyber Security then different topics are already addressed.
81. 12:18The aim was to gain a basic understanding of the safety aspects of the of blockchain technology.
82. 12:24Last year in the blockchain class, to introduce the application possibilities a little bit.
83. 12:31this course was about the safety engineering behind it, how it interacts and how it operates in such a peer-to-peer network, originally trustless, as a situation of trust is created.
84. 12:44There are many, many more details in the blockchain world, There are concepts, there are application-related modifications, which - equipped with this basic knowledge - you will certainly be able to pursue further.
85. 12:58There are also still major tasks for research and development work, many problems are to be solved. Scalability is in question,
86. 13:08the unlikely power consumption is a problem when generating these blocks and there exactly solving this difficult task.
87. 13:19Questions of data protection, usability, these are all things that need to be followed up,
88. 13:24and I hope you enjoyed it, to participate in our openHPI course here.
89. 13:31We've been through this booklet a little bit. at the beginning, where you'll find more details.
90. 13:40A book will be published shortly, You can also download this technical report from the Internet.
91. 13:48Thank you for your attention.

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