New Privacy Problems in Bitcoin clients

[Sergio_Demian_Lerner]

Some new attacks on the privacy of users running a full node in standard clients. Details posted after responsible disclosure and private talks with the dev team.

https://bitslog.wordpress.com/2013/05/31/more-privacy-vulnerabilities-in-bitcoin/

This time I posted in my blog, since I'll try to keep all security/privacy related posts together for easy indexing.

Best regards, Sergio.

[cr1776]

From the post: "But again, the core developers think it’s not worth implementing this fix."

Do you believe that the core developers just do not want to implement the two changes you suggest? Or would they block someone else making those changes and incorporating them?

[Sergio_Demian_Lerner]

From the post: "But again, the core developers think it’s not worth implementing this fix."

Do you believe that the core developers just do not want to implement the two changes you suggest? Or would they block someone else making those changes and incorporating them?

I think that if someone implements them, they may apply the patches.  The decision not to implement them right away may be to a lack of resources to research and implement the patches.

[jackjack]

1. When a checkpoint is reached all blocks that do not belong to the best chain are removed forever from the block chain (or from the inventory)

No need to delete it from the blockchain

2. All block hashes up to the last checkpoint are stored inside the Satoshi client so that no unknown block can be sent.

225000 * 32 bytes = 7200000 bytes = 7.2MB
Not sure it's worth it as 1. is enough