How do Bitcoin and other cryptocurrencies verification services work?

Question

Cryptography

For the last two years, with the popularity of the crypt, I often meet similar services
https://traceer.co
https://www.elliptic.co
https://www.chainalysis.com
https://ciphertrace.com
They analyze transactions on the network on subject of involvement in crime.
The question is what they base their conclusions on on this or that transaction.
Interested in your experience and knowledge in this area.
What are the general algorithms for collecting such data.
Thanks

Answer 1

And there are no special algorithms. Blockchain technology is designed in such a way that it can be validated through the chain. This is the basis of this protocol. On the knee is done in the evening