Daniel Julius Bernstein (sometimes known as djb; born October 29, 1971) is an American German mathematician, cryptologist, and

computer scientist A computer scientist is a person who is trained in the academic study of computer science. Computer scientists typically work on the theoretical side of computation, as opposed to the hardware side on which computer engineers mainly focus (al ...

. He is a visiting professor at CASA at Ruhr University Bochum, as well as a research professor of Computer Science at the University of Illinois at Chicago. Before this, he was a professor (" persoonlijk hoogleraar") in the department of mathematics and computer science at the Eindhoven University of Technology.

Early life

Bernstein attended Bellport High School, a public high school on

Long Island Long Island is a densely populated island in the southeastern region of the U.S. state of New York (state), New York, part of the New York metropolitan area. With over 8 million people, Long Island is the most populous island in the United Sta ...

, graduating in 1987 at the age of 15. The same year, he ranked fifth in the Westinghouse Science Talent Search. In 1987 (at the age of 16), he achieved a Top 10 ranking in the William Lowell Putnam Mathematical Competition. Bernstein earned a B.A. in mathematics from New York University (1991) and a Ph.D. in mathematics from the University of California, Berkeley (1995), where he studied under Hendrik Lenstra.

''Bernstein v. United States''

The export of cryptography from the United States was controlled as a munition starting from the Cold War until recategorization in 1996, with further relaxation in the late 1990s. In 1995, Bernstein brought the court case ''

Bernstein v. United States ''Bernstein v. United States'' is a set of court cases brought by Daniel J. Bernstein challenging restrictions on the export of cryptography from the United States. History The case was first brought in 1995, when Bernstein was a student at ...

''. The ruling in the case declared that software was protected speech under the First Amendment, which contributed to regulatory changes reducing controls on encryption. Bernstein was originally represented by the

Electronic Frontier Foundation The Electronic Frontier Foundation (EFF) is an international non-profit digital rights group based in San Francisco, California. The foundation was formed on 10 July 1990 by John Gilmore, John Perry Barlow and Mitch Kapor to promote Internet ci ...

. He later represented himself.

Cryptography

Bernstein designed the Salsa20

stream cipher stream cipher is a symmetric key cipher where plaintext digits are combined with a pseudorandom cipher digit stream (keystream). In a stream cipher, each plaintext digit is encrypted one at a time with the corresponding digit of the keystream ...

in 2005 and submitted it to eSTREAM for review and possible standardization. He later published the ChaCha20 variant of Salsa in 2008. In 2005, he proposed the elliptic curve Curve25519 as a basis for public-key schemes. He worked as the lead researcher on the Ed25519 version of

EdDSA In public-key cryptography, Edwards-curve Digital Signature Algorithm (EdDSA) is a digital signature scheme using a variant of Schnorr signature based on twisted Edwards curves. It is designed to be faster than existing digital signature scheme ...

. The algorithms made their way into popular software. For example, since 2014, when OpenSSH is compiled without

OpenSSL OpenSSL is a software library for applications that provide secure communications over computer networks against eavesdropping or need to identify the party at the other end. It is widely used by Internet servers, including the majority of HTT ...

they power most of its operations, and

OpenBSD OpenBSD is a security-focused, free and open-source, Unix-like operating system based on the Berkeley Software Distribution (BSD). Theo de Raadt created OpenBSD in 1995 by forking NetBSD 1.0. According to the website, the OpenBSD project em ...

package signing is based on Ed25519. Nearly a decade later,

Edward Snowden Edward Joseph Snowden (born June 21, 1983) is an American and naturalized Russian former computer intelligence consultant who leaked highly classified information from the National Security Agency (NSA) in 2013, when he was an employee and su ...

disclosed mass surveillance by the National Security Agency, and researchers discovered a backdoor in the Agency's Dual_EC_DRBG algorithm. These events raised suspicions of the elliptic curve parameters proposed by NSA and standardized by NIST. Many researchers feared that the NSA had chosen curves that gave them a cryptanalytic advantage. Google selected ChaCha20 along with Bernstein's Poly1305

message authentication code In cryptography, a message authentication code (MAC), sometimes known as a ''tag'', is a short piece of information used for authenticating a message. In other words, to confirm that the message came from the stated sender (its authenticity) and ...

for use in

TLS TLS may refer to: Computing * Transport Layer Security, a cryptographic protocol for secure computer network communication * Thread level speculation, an optimisation on multiprocessor CPUs * Thread-local storage, a mechanism for allocating vari ...

, which is widely used for Internet security. Many protocols based on his works have been adopted by various standards organizations and are used in a variety of applications, such as Apple iOS, the Linux kernel, OpenSSH, and Tor. In spring 2005, Bernstein taught a course on "high speed cryptography." He introduced new attacks against implementations of

AES AES may refer to: Businesses and organizations Companies * AES Corporation, an American electricity company * AES Data, former owner of Daisy Systems Holland * AES Eletropaulo, a former Brazilian electricity company * AES Andes, formerly AES Gener ...

(

cache attack Cache, caching, or caché may refer to: Places United States * Cache, Idaho, an unincorporated community * Cache, Illinois, an unincorporated community * Cache, Oklahoma, a city in Comanche County * Cache, Utah, Cache County, Utah * Cache Coun ...

s) in the same time period. In April 2008, Bernstein's

" Salsa20" was selected as a member of the final portfolio of the eSTREAM project, part of a European Union research directive. In 2011, Bernstein published RFSB, a variant of the Fast Syndrome Based Hash function. He is one of the editors of the 2009 book ''Post-Quantum Cryptography''.

Software

Starting in the mid-1990s, Bernstein has written a number of security-aware programs, including qmail,

ezmlm ezmlm is mailing list management software (MLM) by Daniel J. Bernstein. It is similar to GNU Mailman and Majordomo but only works with the qmail mail transfer agent. It is released into the public domain. The latest version, 0.53, came out i ...

, djbdns, ucspi-tcp, daemontools, and publicfile. Bernstein criticized the leading DNS package at the time, BIND, and wrote djbdns as a DNS package with security as a primary goal. Bernstein offers "security guarantees" for qmail and djbdns in the form of monetary rewards for the identification of flaws. A purported exploit targeting qmail running on 64-bit platforms was published in 2005, but Bernstein believes that the exploit does not fall within the parameters of his qmail security guarantee. In March 2009, Bernstein awarded $1000 to

Matthew Dempsky Matthew may refer to: * Matthew (given name) * Matthew (surname) * ''Matthew'' (ship), the replica of the ship sailed by John Cabot in 1497 * ''Matthew'' (album), a 2000 album by rapper Kool Keith * Matthew (elm cultivar), a cultivar of the C ...

for finding a security flaw in djbdns. In August 2008, Bernstein announced DNSCurve, a proposal to secure the Domain Name System. DNSCurve applies techniques from elliptic curve cryptography to provide a vast increase in performance over the

RSA 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 ...

public-key algorithm used by DNSSEC. It uses the existing DNS hierarchy to propagate trust by embedding public keys into specially formatted, backward-compatible DNS records. Bernstein proposed

Internet Mail 2000 Internet Mail 2000 is an Internet mail architecture proposed by Daniel J. Bernstein (and in subsequent years separately proposed by several others), designed with the precept that the initial storage of mail messages be the responsibility of the ...

, an alternative system for electronic mail, intended to replace the Simple Mail Transfer Protocol (SMTP), the Post Office Protocol (POP3) and the Internet Message Access Protocol (IMAP). Bernstein is also known for his string hashing function ''djb2'' and the cdb database library.

Mathematics

Bernstein has published a number of papers on

mathematics Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. These topics are represented in modern mathematics ...

and

computation Computation is any type of arithmetic or non-arithmetic calculation that follows a well-defined model (e.g., an algorithm). Mechanical or electronic devices (or, historically, people) that perform computations are known as ''computers''. An es ...

. Many of his papers deal with algorithms or implementations. In 2001, Bernstein circulated "Circuits for

integer factorization In number theory, integer factorization is the decomposition of a composite number into a product of smaller integers. If these factors are further restricted to prime numbers, the process is called prime factorization. When the numbers are suf ...

: a proposal," which suggested that, if physical hardware implementations could be brought close to their theoretical efficiency, the then-popular estimates of adequate security parameters might be off by a factor of three. Since 512-bit

was breakable at the time, so might be 1536-bit RSA. Bernstein was careful not to make any actual predictions, and emphasized the importance of correctly interpreting

asymptotic In analytic geometry, an asymptote () of a curve is a line such that the distance between the curve and the line approaches zero as one or both of the ''x'' or ''y'' coordinates tends to infinity. In projective geometry and related contexts, ...

expressions. Several prominent researchers (among them Arjen Lenstra, Adi Shamir, Jim Tomlinson, and Eran Tromer) disagreed strongly with Bernstein's conclusions. Bernstein has received funding to investigate whether this potential can be realized. Bernstein is also the author of the mathematical libraries DJBFFT, a fast portable FFT library, and primegen, an asymptotically fast small prime sieve with low memory footprint based on the sieve of Atkin (rather than the more usual

sieve of Eratosthenes In mathematics, the sieve of Eratosthenes is an ancient algorithm for finding all prime numbers up to any given limit. It does so by iteratively marking as composite (i.e., not prime) the multiples of each prime, starting with the first prime n ...

). Both have been used effectively in the search for large prime numbers. In 2007, Bernstein proposed the use of a (twisted) Edwards curve, Curve25519, as a basis for elliptic curve cryptography; it is employed in Ed25519 implementation of

. In February 2015, Bernstein and others published a paper on stateless post-quantum hash-based signatures, called SPHINCS. In April 2017, Bernstein and others published a paper on Post-Quantum RSA that includes an integer factorization algorithm claimed to be "often much faster than Shor's".https://cr.yp.to/papers/pqrsa-20170419.pdf

Teaching

In 2004, Bernstein taught a course on computer software security where he assigned each student to find ten vulnerabilities in published software. The 25 students discovered 44 vulnerabilities, and the class published security advisories about the issues.

References

External links

*
DJBFFTDaniel Bernstein on the Faculty Page at UICFaculty page at Eindhoven University of Technology
* {{DEFAULTSORT:Bernstein, Daniel J. 1971 births Courant Institute of Mathematical Sciences alumni Living people Modern cryptographers American computer programmers American people of German-Jewish descent 20th-century American mathematicians 21st-century American mathematicians UC Berkeley College of Letters and Science alumni Computer security academics University of Illinois Chicago faculty Computer science educators Eindhoven University of Technology faculty Open content activists People from East Patchogue, New York