olemus
liik digiraha ründeid:
mündi korduv kasutamine maksmiseks

täpsemalt
https://www.youtube.com/watch?annotation_id=annotation_228248261&feature=iv&src_vid=cOc7V64HUDQ&v=phLSjZdDc5A

https://eprint.iacr.org/2012/248.pdf

tõrje
https://www.investopedia.com/ask/answers/061915/how-does-block-chain-prevent-doublespending-bitcoins.asp

https://eprint.iacr.org/2017/394.pdf

vt ka
- topeltmakse