Adam Back, is a Ph.D. in Computer Science, who is widely recognized for his diverse work in cryptography, anonymous systems, and for being one of the earliest members of the movement. cypherpunk.

NIt was born in July 1970 in the city of London, England. He earned a doctorate in computer science from the University of Exeter. Back is primarily recognized for his diverse work on crypto and anonymous systems.

His first job in that regard was; "The Simple Key Search Protocol". Thanks to this work presented in 1995, in conjunction with Andrew Brown y Piete brooks, Netscape SSL security could be broken. Also during your stay in the company Zero Knowledge Systems, Back worked as a company consultant Nokia, in a project to integrate electronic payments using mobile phones.

Adam Back crypto projects

Adam Back has to his credit an extensive list of crypto projects. Among these the most relevant are:

HashCash, your star project

In April 1997, Back presented his well-known work "Hashcash - A Denial of Service Counter-measure". As a consequence of the enormous usefulness of hashcash to prevent DoS attacks on services such as email, Back became a relevant figure in the crypto world.

The mission Back wanted HashCash to accomplish was to curb mass spamming. For it HashCash it required the realization of a small 'computational expense' to be able to send an email. This 'expense' had to be used to calculate a certain hash, complying with the algorithm rules. Doing this in a massive way is hard work for the computer, which leads to consuming cycle of CPU and an increase also in energy consumption. These two situations are the ones that deter spammers from stopping their malicious practices. The first one made sending messages a little slower. The second had a direct impact on the cost of electric bills. Sending an email could cost a few pennies, but sending thousands made that practice financially prohibitive.

“I've been talking about a stamp scheme based on partial hash collision for the last few days on the charts. The idea of ​​using partial hashes, is that they can be expensive to calculate arbitrarily (choosing the desired number collision bits) and yet can be verified instantly. "

Adam Back

Cypherpunks Mail List - Hashcash Presentation - March 28, 1997

In addition to this use, HashCash allowed its use on various systems. One of them was aimed at protecting client-server connections. This since the system could create "Unique markers" for each connection. Thus a server could recognize a genuine connection from a fake connection, protecting users of the service.

Eternity-USENET, a censorship-resistant publishing network

Later in June 1997, A. Back together with Ross Anderson, presented "Eternity-USENET". Eternity is essentially a censorship-resistant information publishing service. To achieve such a feat, this system relied on the operation of PGP to ensure service.  With this project, Back was looking for a way to allow the publication of information anonymously. All this on a distributed infrastructure resistant to censorship by governments or malicious third parties.

Improvements to the PGP signature system

Then in June 1998, "Non-transferable signatures using PGP". This work was presented together with Ian Brown, and explained how a system would be able to perform non-transferable signatures using PGP. With this, he managed to improve the security level of the PGP system. Something that Back used a lot on mailing lists and that he still uses today, within other communication systems.

The Freedom 2.0 Mail System

Later in 2000, Back presented the work. Freedom 2.0 Mail system. With this, A. Back sought to implement and design a new email system focused on privacy. Later in 2001, he presented a review of that work, correcting some problems detected in his first presentation, and taking new security considerations.

credlib, a library for secure credential management

Back in 2001 Back designed a bookstore called credlib. This bookstore is based on OpenSSL and it was created in order to create a simple interface to use the credentials Brands o ChaumThe main objective of this project was to improve public key infrastructures (PKI). For this, Back designed this library in order to strengthen the credential authentication means. While for the moment, credlib it was quite an advance, its use was put aside. This was because the algorithm used by Back in his design, the SHA-1, began to show signs of vulnerability soon after.

Onion, a forerunner of Tor

In June 2002, Back presented another of his biggest projects. "Onion". A system designed to create anonymous connection tunnels. The objective of this project was to make the IP addresses of its users anonymous, while they could surf the Internet. With this, Back created a tunnel system to bypass censorship. All under a less complex and secure system compared to VPNs and / or proxies. This development is a prelude to what the famous network would become Tor shortly after.

Cypherspace, a space for the crypto community

By September 2003, Back added another job to his long list of projects, the website Cypherspace. This website quickly became a benchmark for the crypto community. It also hosted numerous developments around new cryptographic systems aimed at privacy and anonymity. Furthermore, it was also the cradle of many digital currency projects, such as B-money y Digicash, Among others.

Current projects

Back is currently the Executive Director of Blockstream, a company that seeks to promote the development of Bitcoin and Blockchain technology. From there it has promoted in many ways the adoption and development of blockchain technology. Taking different projects like c-lightning, Liquidity Network, Blockstream satellite y Elements. All of them unique technologies that serve to enhance the capabilities of blockchain and its adoption in the world.

Its relevance in the design of Bitcoin

Although Adam Back was not involved in the development of Bitcoin, his name is present in the white paper. This is because Satoshi Nakamoto, was inspired by HashCash to design Bitcoin. The presence of this inspiration is seen in the algorithm of Work test of Bitcoin, as well as, in the Bitcoin block identification system. In fact, the same Nakamoto He contacted Adam Back in 2009 to learn more about HashCash. This in order to know if the protocol could be applied on a much larger and more complex scale.

Back never suspected Nakamoto was a pseudonym and never met Nakamoto in person. This fact makes Back one of the few people who have actually communicated with Nakamoto.