More Privacy Vulnerabilities in Bitcoin
Posted by SDLerner in Uncategorized on May 31, 2013
If you plan to stay anonymous while using Bitcoin, then you have to take many precautions, and you may even have to compile your own fork of the Satoshi client. During the Bitcoin Conference 2013 (which, BTW, was terribly fun), I found two new problems with Bitcoin privacy. I call them “vulnerabilities” but you may […]
P2PTradeX, back from the future
Posted by SDLerner in Uncategorized on May 20, 2013
Almost one year ago I described in the Bitcoin technical forums a new P2P virtual coin trading protocol (so called P2PTradeX) I had implemented for an alternate cryptocoin, mostly as a proof of concept. The idea got some attention, but nobody really needed that stuff. It was before it’s time. Yesterday I was at Bitcoin […]
Satoshi ‘s Fortune: a more accurate figure
Posted by SDLerner in Uncategorized on April 24, 2013
Since yesterday, my post was read 30k times in just one day. So a lot of people started asking me how precise was my analysis, since I had estimated the figure just by looking at the graph. People want a more rigorous analysis. Today I carefully masked all blocks that were not part of Satoshi […]
More on block mining history: 1st half of 2010
Posted by SDLerner in Uncategorized on April 17, 2013
This post is a follow up of my previous post. I’m showing another interesting graph. It shows how Satoshi mining pattern disappears in approximately MAY 2010. Click on the image to see it clearer.
The Well Deserved Fortune of Satoshi Nakamoto, Bitcoin creator, Visionary and Genius
Posted by SDLerner in Uncategorized on April 17, 2013
I won’t discuss anything in this post. I’m tired of discussing technical things with people with skewed opinions and monetary interest. I’ve talked enough in the Bitcointalk forum about Satoshi. Some people screamed at me. But a picture is worth a thousand words. And I will show pictures that everyone can replicate. Please forgive me for the […]
Dos and Don’ts (but mostly Don’ts) for Secure Transport Protocol Designers
Posted by SDLerner in Uncategorized on March 20, 2013
Everybody tells you: don’t invent your own crypto. Nevertheless, you fell the need to design a protocol for your own, a passion. Why? Because it’s fun, and because by failing you will learn a lot. And you will never forget the lesson. So this time I encourage you to invent your own secure transport protocol, […]
Comparison between HC Modes and a Stream Cipher based on a Hash function Chain
Posted by SDLerner in Uncategorized on March 18, 2013
In my first post about HC modes I presented six block cipher modes of operation that provide forward secrecy right at the block level. These schemes rely on a ideal hash function to provide forward secrecy and privacy (this last property also requires an ideal block cipher). It turns out that this is not the […]
Comparison between forward secrecy of HC modes, SCIMP and ZRTP
Posted by SDLerner in Uncategorized on February 26, 2013
One of the things some people have asked me is what the difference between the HC modes and the forward secrecy provided by protocols such as SCIMP or ZRTP. SCIMP has a one-way key derivation, similar to my Hash Chain Prefix (HCP) mode. Since it is supposed that messages sent are short, I see no […]
An imaginative use case for the HC encryption modes
Posted by SDLerner in Uncategorized on February 25, 2013
In my previous post I presented some modes of operation of block ciphers to provide forward secrecy. Today I will let my imagination fly over Hollywood with this use case: Suppose Alice, a US secret agent working in China, has managed to break into a computer from a top-secret Chinese government agency and she has […]
Block ciphers modes with forward secrecy for Cryptocat/OTR
Posted by SDLerner in Uncategorized on February 22, 2013
Off-the-Record Messaging (OTR) is a protocol that allows people to chat in realtime securely and privately. One of the most interesting features I’ve found in OTR is the ability to provide Perfect Forward Secrecy (PFS). Simply stated, an encryption system provides forward secrecy if even if suddenly all private keys in existence are compromised, an […]
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