Ralph C. Merkle (born February 2, 1952) is a computer scientist and mathematician. He is one of the inventors of

public-key cryptography Public-key cryptography, or asymmetric cryptography, is the field of cryptographic systems that use pairs of related keys. Each key pair consists of a public key and a corresponding private key. Key pairs are generated with cryptographic alg ...

, the inventor of

cryptographic hash A cryptographic hash function (CHF) is a hash algorithm (a map of an arbitrary binary string to a binary string with fixed size of n bits) that has special properties desirable for cryptography: * the probability of a particular n-bit output ...

ing, and more recently a researcher and speaker on

cryonics Cryonics (from el, κρύος ''kryos'' meaning 'cold') is the low-temperature freezing (usually at ) and storage of human remains, with the speculative hope that resurrection may be possible in the future. Cryonics is regarded with skepticis ...

Contributions

While an undergraduate, Merkle devised Merkle's Puzzles, a scheme for communication over an

insecure channel In cryptography, a secure channel is a means of data transmission that is resistant to overhearing and tampering. A confidential channel is a means of data transmission that is resistant to overhearing, or eavesdropping (e.g., reading the conten ...

, as part of a class project. The scheme is now recognized to be an early example of

public key cryptography Public-key cryptography, or asymmetric cryptography, is the field of cryptographic systems that use pairs of related keys. Each key pair consists of a public key and a corresponding private key. Key pairs are generated with cryptographic alg ...

. He co-invented the

Merkle–Hellman knapsack cryptosystem The Merkle–Hellman knapsack cryptosystem was one of the earliest public key cryptosystems. It was published by Ralph Merkle and Martin Hellman in 1978. A polynomial time attack was published by Adi Shamir in 1984. As a result, the cryptosystem is ...

, invented

cryptographic hashing A cryptographic hash function (CHF) is a hash algorithm (a map of an arbitrary binary string to a binary string with fixed size of n bits) that has special properties desirable for cryptography: * the probability of a particular n-bit output re ...

(now called the

Merkle–Damgård construction In cryptography, the Merkle–Damgård construction or Merkle–Damgård hash function is a method of building collision-resistant cryptographic hash functions from collision-resistant one-way compression functions. Goldwasser, S. and Bellare, M ...

based on a pair of articles published 10 years later that established the security of the scheme), and invented

Merkle tree In cryptography and computer science, a hash tree or Merkle tree is a tree in which every "leaf" (node) is labelled with the cryptographic hash of a data block, and every node that is not a leaf (called a ''branch'', ''inner node'', or ''inode'') ...

s. The Merkle–Damgård construction is at the heart of many hashing algorithms. While at

Xerox PARC PARC (Palo Alto Research Center; formerly Xerox PARC) is a research and development company in Palo Alto, California. Founded in 1969 by Jacob E. "Jack" Goldman, chief scientist of Xerox Corporation, the company was originally a division of Xero ...

, Merkle designed the

Khufu and Khafre In cryptography, Khufu and Khafre are two block ciphers designed by Ralph Merkle in 1989 while working at Xerox's Palo Alto Research Center. Along with Snefru, a cryptographic hash function, the ciphers were named after the Egyptian Pharaohs Khuf ...

block cipher In cryptography, a block cipher is a deterministic algorithm operating on fixed-length groups of bits, called ''blocks''. Block ciphers are specified cryptographic primitive, elementary components in the design of many cryptographic protocols and ...

s, and the

Snefru Snefru is a cryptographic hash function invented by Ralph Merkle in 1990 while working at Xerox PARC. The function supports 128-bit and 256-bit output. It was named after the Egyptian Pharaoh Sneferu, continuing the tradition of the Khufu and Kh ...

hash function.

Career

Merkle was the manager of

compiler In computing, a compiler is a computer program that translates computer code written in one programming language (the ''source'' language) into another language (the ''target'' language). The name "compiler" is primarily used for programs that ...

development at

Elxsi Elxsi Corporation was a minicomputer manufacturing company established in the late 1970s in Silicon Valley, USA, along with a host of competitors ( Trilogy Systems, Sequent, Convex Computer). The Elxsi processor was an Emitter Coupled Logic (ECL) d ...

from 1980. In 1988, he became a research scientist at

. In 1999 he became a nanotechnology theorist for

Zyvex Zyvex is a molecular nanotechnology company, founded by James R. Von Ehr II in 1997. In April 2007, the corporation split into four components: Zyvex Technologies, Zyvex Instruments (focused on tools, instrumentation, and applications for the s ...

. In 2003 he became a

Distinguished Professor Distinguished Professor is an academic title given to some top tenured professors in a university, school, or department. Some distinguished professors may have endowed chairs. In the United States Often specific to one institution, titles such ...

Georgia Tech The Georgia Institute of Technology, commonly referred to as Georgia Tech or, in the state of Georgia, as Tech or The Institute, is a public research university and institute of technology in Atlanta, Georgia. Established in 1885, it is part of ...

, where he led the

Georgia Tech Information Security Center Georgia most commonly refers to: * Georgia (country), a country in the Caucasus region of Eurasia * Georgia (U.S. state), a state in the Southeast United States Georgia may also refer to: Places Historical states and entities * Related to the ...

. In 2006 he returned to the San Francisco Bay Area, where he has been a senior research fellow at IMM, a faculty member at

Singularity University Singularity Education Group (using the public names Singularity Group, Singularity University or SingularityU) is an American company that offers executive educational programs, a business incubator, and business consultancy services. Although ...

, and a board member of the

Alcor Life Extension Foundation The Alcor Life Extension Foundation, most often referred to as Alcor, is an American nonprofit, federally tax-exempt, 501(c)(3) organization based in Scottsdale, Arizona, United States. Alcor advocates for, researches, and performs cryonics, th ...

. He was awarded the

IEEE Richard W. Hamming Medal The IEEE Richard W. Hamming Medal is presented annually to up to three persons, for outstanding achievements in information sciences, information systems and information technology. The recipients receive a gold medal, together with a replica in ...

in 2010. He is active in the field of molecular manipulation and self-replicating machines and has published books on the subject.

Personal life

Ralph Merkle is a grandnephew of baseball star

Fred Merkle Carl Frederick Rudolf Merkle (also sometimes documented as Frederick Charles Merkle; December 20, 1888 – March 2, 1956), nicknamed "Bonehead", was an American first baseman in Major League Baseball from 1907 to 1926. Although he had a lengthy c ...

; son of Theodore Charles Merkle, director of

Project Pluto Project Pluto was a United States government program to develop nuclear-powered ramjet engines for use in cruise missiles. Two experimental engines were tested at the Nevada Test Site (NTS) in 1961 and 1964 respectively. On 1 January 1957, t ...

; and brother of

Judith Merkle Riley Judith Merkle Riley (January 14, 1942 – September 12, 2010) was an American writer, teacher and academic who wrote six historical romance novels. Biography Judith Astria Merkle was born in 1942 and grew up in Livermore, California. Her grea ...

, a historical writer. Merkle is married to

Carol Shaw Carol Shaw (born 1955) is one of the first female game designers and programmers in the video game industry. She is best known for creating the Atari 2600 vertically scrolling shooter ''River Raid'' (1982) for Activision. She worked for Atari, In ...

, the video game designer best known for the 1982 Atari 2600 game, ''

River Raid ''River Raid'' is a vertically scrolling shooter designed and programmed by Carol Shaw and published by Activision in 1982 for the Atari 2600 video game console. Over a million game cartridges were sold. Activision later ported the title to th ...

''. Merkle is on the board of directors of the

organization

. Merkle appears in the

science fiction Science fiction (sometimes shortened to Sci-Fi or SF) is a genre of speculative fiction which typically deals with imaginative and futuristic concepts such as advanced science and technology, space exploration, time travel, parallel unive ...

novel ''

The Diamond Age ''The Diamond Age: Or, A Young Lady's Illustrated Primer'' is a science fiction novel by American writer Neal Stephenson. It is to some extent a Bildungsroman or coming-of-age story, focused on a young girl named Nell, set in a future world in ...

'', involving nanotechnology.

Awards

* 1996

Paris Kanellakis Award The Paris Kanellakis Theory and Practice Award is granted yearly by the Association for Computing Machinery (ACM) to honor "specific theoretical accomplishments that have had a significant and demonstrable effect on the practice of computing". It wa ...

(from the ACM) for the Invention of

Public Key Cryptography Public-key cryptography, or asymmetric cryptography, is the field of cryptographic systems that use pairs of related keys. Each key pair consists of a public key and a corresponding private key. Key pairs are generated with cryptographic alg ...

. * 1998

Feynman Prize in Nanotechnology The Feynman Prize in Nanotechnology is an award given by the Foresight Institute for significant advances in nanotechnology. Two prizes are awarded annually, in the categories of experimental and theoretical work. There is also a separate chall ...

for computational modeling of molecular tools for atomically-precise chemical reactions * 1999

IEEE Koji Kobayashi Computers and Communications Award The IEEE Koji Kobayashi Computers and Communications Award is a Technical Field Award of the IEEE established in 1986. This award has been presented annually since 1988 for outstanding contributions to the integration of computers and commun ...

* 2000

RSA Award for Excellence in Mathematics RSA may refer to: Organizations Academia and education * Rabbinical Seminary of America, a yeshiva in New York City *Regional Science Association International (formerly the Regional Science Association), a US-based learned society *Renaissance S ...

for the invention of public key cryptography. * 2008 International Association for Cryptographic Research (IACR) fellow for the invention of public key cryptography. * 2010

IEEE The Institute of Electrical and Electronics Engineers (IEEE) is a 501(c)(3) professional association for electronic engineering and electrical engineering (and associated disciplines) with its corporate office in New York City and its operation ...

Hamming Medal for the invention of public key cryptography * 2011

Computer History Museum The Computer History Museum (CHM) is a museum of computer history, located in Mountain View, California. The museum presents stories and artifacts of Silicon Valley and the information age, and explores the computing revolution and its impact on ...

Fellow "for his work, with Whitfield Diffie and Martin Hellman, on public key cryptography." * 2011

National Inventors Hall of Fame The National Inventors Hall of Fame (NIHF) is an American not-for-profit organization, founded in 1973, which recognizes individual engineers and inventors who hold a U.S. patent of significant technology. Besides the Hall of Fame, it also opera ...

, for the invention of public key cryptography * 2012

National Cyber Security Hall of Fame The National Cyber Security Hall of Fame, founded by Larry Letow and Rick Geritz, was established in 2012 to recognize the contributions of key individuals in the field of cyber security; its mission statement is, ''Respect the Past - Protect the F ...

inductee

References

* Ralph C. Merkle, ''Secrecy, authentication, and public key systems'' (Computer science), UMI Research Press, 1982, . *

Robert A. Freitas Jr. Robert A. Freitas Jr. (born 1952) is an American nanotechnologist. Career In 1974, Freitas earned a bachelor's degree in both physics and psychology from Harvey Mudd College, and in 1978, he received a Juris Doctor (J.D.) degree from Santa Clar ...

, Ralph C. Merkle, ''Kinematic Self-Replicating Machines'', Landes Bioscience, 2004, . * Paul Kantor (Ed), Gheorghe Mureşan (Ed), Fred Roberts (Ed), Daniel Zeng (Ed), Frei-Yue Wang (Ed),

Hsinchun Chen Hsinchun Chen is the Regents' Professor and Thomas R. Brown Chair of Management and Technology at the University of Arizona and the Director and founder of the Artificial Intelligence Lab (AI Lab). He also served as lead program director of the Sm ...

(Ed), Ralph Merkle (Ed), "Intelligence and Security Informatics" : ''IEEE International Conference on Intelligence and Security Informatics'', ISI 2005, Atlanta, GA, US, May 19–20, ... (

Lecture Notes in Computer Science ''Lecture Notes in Computer Science'' is a series of computer science books published by Springer Science+Business Media since 1973. Overview The series contains proceedings, post-proceedings, monographs, and Festschrifts. In addition, tutorials, ...

), Springer, 2005, .
Interview
at

Google Videos Google Search (also known simply as Google) is a search engine provided by Google. Handling more than 3.5 billion searches per day, it has a 92% share of the global search engine market. It is also the most-visited website in the world. The ...

in the Death in the Deep Freeze documentary (August 2, 2006)
Nova Southeastern University, Nanotechnology Expert Ralph Merkle to Speak on "Life and Death"
(August 2008)

External links

Oral history interview with Martin Hellman
from 2004, Palo Alto, California.

Charles Babbage Institute The IT History Society (ITHS) is an organization that supports the history and scholarship of information technology by encouraging, fostering, and facilitating archival and historical research. Formerly known as the Charles Babbage Foundation, ...

, University of Minnesota, Minneapolis.

Hellman Hellman is a surname. Notable people with the surname include: * Åke Hellman (1915–2017), Finnish centenarian, painter, and art professor *Bonnie Hellman (born 1950), American actress *C. Doris Hellman (1910–1973), American historian of scienc ...

describes his invention of

with collaborators

Whitfield Diffie Bailey Whitfield 'Whit' Diffie (born June 5, 1944), ForMemRS, is an American cryptographer and mathematician and one of the pioneers of public-key cryptography along with Martin Hellman and Ralph Merkle. Diffie and Hellman's 1976 paper ''New Dire ...

and Ralph Merkle at Stanford University in the mid-1970s. He also relates his subsequent work in cryptography with Steve Pohlig (the Pohlig–Hellman system) and others. {{DEFAULTSORT:Merkle, Ralph 1952 births Living people American cryptographers American people of Swiss descent Cryonicists Modern cryptographers American nanotechnologists Georgia Tech faculty 20th-century American inventors International Association for Cryptologic Research fellows Scientists at PARC (company) Computer security academics