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  • Ankur Sawhney thinks this is interesting:

There were multiple issues with the schemes described in infeasible preceding paragraphs. These problems range from no clear solution of disagreements between nodes to reliance on a central trusted third party and trusted timestamping.

From

Cover of Mastering Blockchain

Note

The issues with bitcoins predecessors - 1) Unable to build consensus, 2) Reliance on a dentral third party timestamp provider