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Public-key cryptography

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known to be compromised because the data appears fine to the other user. This can lead to confusing disagreements between users such as "it must be on your end!" when neither user is at fault. Hence, man-in-the-middle attacks are only fully preventable when the communications infrastructure is physically controlled by one or both parties; such as via a wired route inside the sender's own building. In summation, public keys are easier to alter when the communications hardware used by a sender is controlled by an attacker.
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blocks and encrypted messages. Only the intended recipient is able to decrypt the metadata block, and having done so they can identify and download their messages and decrypt them. Such a messaging system is at present in an experimental phase and not yet deployed. Scaling this method would reveal to the third party only the inbox server being used by the recipient and the timestamp of sending and receiving. The server could be shared by thousands of users, making social network modelling much more challenging.
356:, in which a message is signed with the sender's private key and can be verified by anyone who has access to the sender's public key. This verification proves that the sender had access to the private key, and therefore is very likely to be the person associated with the public key. It also proves that the signature was prepared for that exact message, since a signature that passes verification with the public key on one message will not pass verification with the public key on other messages. 160: 151: 177: 135: 38: 525:– is out of reach of all potential attackers. In many cases, the work factor can be increased by simply choosing a longer key. But other algorithms may inherently have much lower work factors, making resistance to a brute-force attack (e.g., from longer keys) irrelevant. Some special and specific algorithms have been developed to aid in attacking some public key encryption algorithms; both 557:, in which the communication of public keys is intercepted by a third party (the "man in the middle") and then modified to provide different public keys instead. Encrypted messages and responses must, in all instances, be intercepted, decrypted, and re-encrypted by the attacker using the correct public keys for the different communication segments so as to avoid suspicion. 335:. This requirement is never trivial and very rapidly becomes unmanageable as the number of participants increases, or when secure channels are not available, or when, (as is sensible cryptographic practice), keys are frequently changed. In particular, if messages are meant to be secure from other users, a separate key is required for each possible pair of users. 670:, two parties would rely upon a key that they would exchange by means of a secure, but non-cryptographic, method such as a face-to-face meeting, or a trusted courier. This key, which both parties must then keep absolutely secret, could then be used to exchange encrypted messages. A number of significant practical difficulties arise with this approach to 609:
scheme were not used at all. An attacker who penetrates an authority's servers and obtains its store of certificates and keys (public and private) would be able to spoof, masquerade, decrypt, and forge transactions without limit, assuming that they were able to place themselves in the communication stream.
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As with all security-related systems, there are various potential weaknesses in public-key cryptography. Aside from poor choice of an asymmetric key algorithm (there are few that are widely regarded as satisfactory) or too short a key length, the chief security risk is that the private key of a pair
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in the message header, which might include the identities of the sender and recipient, the sending date, subject field, and the software they use etc. Rather, only the body of the message is concealed and can only be decrypted with the private key of the intended recipient. This means that a third
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key from the server to client has the advantage of not requiring that a symmetric key be pre-shared manually, such as on printed paper or discs transported by a courier, while providing the higher data throughput of symmetric key cryptography over asymmetric key cryptography for the remainder of the
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For example, a software publisher can create a signature key pair and include the public key in software installed on computers. Later, the publisher can distribute an update to the software signed using the private key, and any computer receiving an update can confirm it is genuine by verifying the
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scheme, each party generates a public/private key pair and distributes the public key of the pair. After obtaining an authentic (n.b., this is critical) copy of each other's public keys, Alice and Bob can compute a shared secret offline. The shared secret can be used, for instance, as the key for a
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However, there has been a recent demonstration of messaging with encrypted headers, which obscures the identities of the sender and recipient, and significantly reduces the available metadata to a third party. The concept is based around an open repository containing separately encrypted metadata
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In some advanced man-in-the-middle attacks, one side of the communication will see the original data while the other will receive a malicious variant. Asymmetric man-in-the-middle attacks can prevent users from realizing their connection is compromised. This remains so even when one user's data is
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of the certificate authority and then, in a second step, the certificates of potential communicators. An attacker who could subvert one of those certificate authorities into issuing a certificate for a bogus public key could then mount a "man-in-the-middle" attack as easily as if the certificate
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For example, the certificate authority issuing the certificate must be trusted by all participating parties to have properly checked the identity of the key-holder, to have ensured the correctness of the public key when it issues a certificate, to be secure from computer piracy, and to have made
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Public key encryption, in which a message is encrypted with the intended recipient's public key. For properly chosen and used algorithms, messages cannot in practice be decrypted by anyone who does not possess the matching private key, who is thus presumed to be the owner of that key and so the
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One important issue is confidence/proof that a particular public key is authentic, i.e. that it is correct and belongs to the person or entity claimed, and has not been tampered with or replaced by some (perhaps malicious) third party. There are several possible approaches, including:
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For example, a journalist can publish the public key of an encryption key pair on a web site so that sources can send secret messages to the news organization in ciphertext. Only the journalist who knows the corresponding private key can decrypt the ciphertexts to obtain the sources'
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is used with the underlying algorithm by both the sender and the recipient, who must both keep it secret. Of necessity, the key in every such system had to be exchanged between the communicating parties in some secure way prior to any use of the system – for instance, via a
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In an asymmetric key encryption scheme, anyone can encrypt messages using a public key, but only the holder of the paired private key can decrypt such a message. The security of the system depends on the secrecy of the private key, which must not become known to any
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are typically valid for several years at a time, so the associated private keys must be held securely over that time. When a private key used for certificate creation higher in the PKI server hierarchy is compromised, or accidentally disclosed, then a
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must be considered when deploying public key systems. Some certificate authority – usually a purpose-built program running on a server computer – vouches for the identities assigned to specific private keys by producing a digital certificate.
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signature using the public key. As long as the software publisher keeps the private key secret, even if a forger can distribute malicious updates to computers, they cannot convince the computers that any malicious updates are genuine.
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with Alice's private key, but the message itself is not encrypted. 1) Alice signs a message with her private key. 2) Using Alice's public key, Bob can verify that Alice sent the message and that the message has not been
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A man-in-the-middle attack can be difficult to implement due to the complexities of modern security protocols. However, the task becomes simpler when a sender is using insecure media such as public networks, the
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that exploit information leakage to simplify the search for a secret key. These are often independent of the algorithm being used. Research is underway to both discover, and to protect against, new attacks.
2341:, Chapter 6 of "Understanding Cryptography, A Textbook for Students and Practitioners". (companion web site contains online cryptography course that covers public-key cryptography), Springer, 2009. 757:. Both organisations had a military focus and only limited computing power was available in any case; the potential of public key cryptography remained unrealised by either organization: 761:
I judged it most important for military use ... if you can share your key rapidly and electronically, you have a major advantage over your opponent. Only at the end of the evolution from
815:, and was invented in 1974 and only published in 1978. This makes asymmetric encryption a rather new field in cryptography although cryptography itself dates back more than 2,000 years. 564:"). These terms refer to reading the sender's private data in its entirety. A communication is particularly unsafe when interceptions can not be prevented or monitored by the sender. 572:, or wireless communication. In these cases an attacker can compromise the communications infrastructure rather than the data itself. A hypothetical malicious staff member at an 314:) use both symmetric encryption and asymmetric encryption, often by using asymmetric encryption to securely exchange a secret key, which is then used for symmetric encryption. 654:
party could construct quite a detailed model of participants in a communication network, along with the subjects being discussed, even if the message body itself is hidden.
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said: "Jevons anticipated a key feature of the RSA Algorithm for public key cryptography, although he certainly did not invent the concept of public key cryptography."
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By contrast, in a public key system, the public keys can be disseminated widely and openly, and only the corresponding private keys need be kept secret by its owner.
1975: 854:, to encrypt and decrypt, performing both public key encryption and public key digital signatures. Its security is connected to the extreme difficulty of 223:. Security of public-key cryptography depends on keeping the private key secret; the public key can be openly distributed without compromising security. 509:, many asymmetric key algorithms are considered vulnerable to attacks, and new quantum-resistant schemes are being developed to overcome the problem. 1637:
Stohrer, Christian; Lugrin, Thomas (2023), Mulder, Valentin; Mermoud, Alain; Lenders, Vincent; Tellenbach, Bernhard (eds.), "Asymmetric Encryption",
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Since the 1970s, a large number and variety of encryption, digital signature, key agreement, and other techniques have been developed, including the
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was found to be insecure after the development of a new attack. As with all cryptographic functions, public-key implementations may be vulnerable to
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have known attacks that are much faster than the brute-force approach. None of these are sufficiently improved to be actually practical, however.
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Because asymmetric key algorithms are nearly always much more computationally intensive than symmetric ones, it is common to use a public/private
1778: 734:(GCHQ), conceived of the possibility of "non-secret encryption", (now called public key cryptography), but could see no way to implement it. 1727:"What Is a Man-in-the-Middle Attack and How Can It Be Prevented – What is the difference between a man-in-the-middle attack and sniffing?" 306:, asymmetric encryption is rather slow compared to good symmetric encryption, too slow for many purposes. Today's cryptosystems (such as 407:– a message that a sender encrypts using the recipient's public key, which can be decrypted only by the recipient's paired private key. 921: 1834:
Bjorgvinsdottir, Hanna; Bentley, Phil (24 June 2021). "Warp2: A Method of Email and Messaging with Encrypted Addressing and Headers".
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These discoveries were not publicly acknowledged for 27 years, until the research was declassified by the British government in 1997.
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systems use digital signatures to ensure that one party cannot successfully dispute its authorship of a document or communication.
383:" decentralizes authentication by using individual endorsements of links between a user and the public key belonging to that user. 55: 2057: 17: 2413: 731: 81: 2366: 2295: 2127: 1682: 1656: 960: 432: 858:, a problem for which there is no known efficient general technique. A description of the algorithm was published in the 617: 88: 803:'s work on public key distribution, disclosed a method of public key agreement. This method of key exchange, which uses 560:
A communication is said to be insecure where data is transmitted in a manner that allows for interception (also called "
2448: 620:, which are commonly used to provide security for web browser transactions (for example, most websites utilize TLS for 521:". However, such an attack is impractical if the amount of computation needed to succeed – termed the "work factor" by 376:
relies upon this. This implies that the PKI system (software, hardware, and management) is trust-able by all involved.
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discusses the circumstances and fundamental insights of his invention of public key cryptography with collaborators
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arrangements with all participants to check all their certificates before protected communications can begin.
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Despite its theoretical and potential problems, Public key infrastructure is widely used. Examples include
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The most obvious application of a public key encryption system is for encrypting communication to provide
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messages—an eavesdropper reading email on its way to the journalist cannot decrypt the ciphertexts.
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of electronic communications and data storage. They underpin numerous Internet standards, such as
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Aside from the resistance to attack of a particular key pair, the security of the certification
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digital certificates and manage public-key encryption. However, this has potential weaknesses.
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Major weaknesses have been found for several formerly promising asymmetric key algorithms. The
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Another potential security vulnerability in using asymmetric keys is the possibility of a
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Alvarez, Rafael; Caballero-Gil, Cándido; Santonja, Juan; Zamora, Antonio (27 June 2017).
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becomes known. All security of messages, authentication, etc., will then be lost.
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Examples of well-regarded asymmetric key techniques for varied purposes include:
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Can the reader say what two numbers multiplied together will produce the number
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Escribano Pablos, José Ignacio; González Vasco, María Isabel (April 2023).
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system, a sender can use a private key together with a message to create a
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In 1977, a generalization of Cocks's scheme was independently invented by
2017: 1455:. Vol. 44. MSRI Publications. §5: Public-key signatures, pp. 543–545 999: 601: 2128:"A Method for Obtaining Digital Signatures and Public-Key Cryptosystems" 1711: 1282: 150: 1606: 1597: 1132: 1017:
Examples of notable – yet insecure – asymmetric key algorithms include:
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Most of the available public-key encryption software does not conceal
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Understanding Cryptography: A Textbook for Students and Practitioners
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Examples of asymmetric key algorithms not yet widely adopted include:
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An account of how GCHQ kept their invention of PKE secret until 1997
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The Principles of Science: A Treatise on Logic and Scientific Method
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23rd Annual Symposium on Foundations of Computer Science (SFCS 1982)
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Public key algorithms are fundamental security primitives in modern
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system, anyone with a public key can encrypt a message, yielding a
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person associated with the public key. This can be used to ensure
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IEEE 1363: Standard Specifications for Public-Key Cryptography
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Examples of protocols using asymmetric key algorithms include:
142:) number is used to begin generation of an acceptable pair of 2002: 1055: 1005: 975: 941: 937: 851: 621: 395:
system for digitally signing emails also uses this approach.
773:... did public key cryptography realise its full potential. 698:? I think it unlikely that anyone but myself will ever know. 488:
cryptography-based key exchange to share a server-generated
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family of schemes use this procedure; they are thus called
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that use pairs of related keys. Each key pair consists of a
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One approach to prevent such attacks involves the use of a
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Two of the best-known uses of public key cryptography are:
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Cryptography and Network Security: Principles and Practice
1950:"The Possibility of Secure Non-secret Digital Encryption" 1913:
Golob, Solomon W. (1996). "On Factoring Jevons' Number".
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DSS (Digital Signature Standard), which incorporates the
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In 1976, an asymmetric key cryptosystem was published by
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to cryptography, and went on to discuss specifically the
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Bernstein, Daniel J.; Lange, Tanja (14 September 2017).
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All public key schemes are in theory susceptible to a "
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Further applications built on this foundation include:
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Another application in public key cryptography is the
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Rivest, R.; Shamir, A.; Adleman, L. (February 1978).
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Trends in Data Protection and Encryption Technologies
834:. The latter authors published their work in 1978 in 368:(PKI), in which one or more third parties – known as 2125: 414:. Digital signature schemes can be used for sender 62:. Unsourced material may be challenged and removed. 1671:Paar, Christof; Pelzl, Jan; Preneel, Bart (2010). 387:uses this approach, in addition to lookup in the 27:Cryptographic system with public and private keys 2420: 2246: 1670: 146:suitable for use by an asymmetric key algorithm. 1886: 1256: 842:column, and the algorithm came to be known as 322:Before the mid-1970s, all cipher systems used 2040: 1998:"GCHQ pioneers on birth of public key crypto" 1636: 2228:"SSL/TLS Strong Encryption: An Introduction" 1857: 1406:(October 1996). "8: Public-key encryption". 1358:(October 1996). "8: Public-key encryption". 765:designing an open internet architecture for 583: 548: 2276: 2034: 1557: 2392:Oral history interview with Martin Hellman 1436: 922:Elliptic Curve Digital Signature Algorithm 753:. The scheme was also passed to the US's 466:for a symmetric key encryption algorithm. 2339:"Introduction to Public-Key Cryptography" 2148: 2070: 1839: 1779:"China, GitHub and the man-in-the-middle" 1770: 1646: 1605: 1509: 1491: 1476:"Algorithms for Lightweight Key Exchange" 1442: 1388: 1319: 1231: 1219: 741:implemented what has become known as the 122:Learn how and when to remove this message 2410:at Stanford University in the mid-1970s. 2194: 1991: 1989: 1853: 1851: 1801: 175: 158: 149: 133: 2344: 2058:IEEE Transactions on Information Theory 1995: 1750: 1724: 721: 644: 442: 14: 2421: 2090:from the original on 29 November 2014. 1776: 1697: 1340: 1213: 769:, its adaptation and adoption for the 732:Government Communications Headquarters 702:Here he described the relationship of 462:to transmit data using the now-shared 138:An unpredictable (typically large and 2016: 2010: 1986: 1973: 1947: 1912: 1848: 1807: 1223:Internet Security Glossary, Version 2 282:. Some public key algorithms provide 1880: 1023:Merkle–Hellman knapsack cryptosystem 989:authenticated key agreement protocol 961:password-authenticated key agreement 730:, a British cryptographer at the UK 433:password-authenticated key agreement 60:adding citations to reliable sources 31: 2283:Introduction to Modern Cryptography 2119: 1558:Mihir, Bellare; Goldwasser, Shafi. 862:column in the August 1977 issue of 786: 24: 2225: 372:– certify ownership of key pairs. 25: 2470: 2385: 1751:Tunggal, Abi (20 February 2020). 1725:Tunggal, Abi (20 February 2020). 1320:Stallings, William (3 May 1990). 749:, developed what is now known as 505:Additionally, with the advent of 2315:Handbook of Applied Cryptography 2050:"New Directions in Cryptography" 1996:Espiner, Tom (26 October 2010). 1974:Sawer, Patrick (11 March 2016). 1948:Ellis, James H. (January 1970). 1560:"Chapter 10: Digital signatures" 1409:Handbook of Applied Cryptography 1361:Handbook of Applied Cryptography 846:, from their initials. RSA uses 805:exponentiation in a finite field 298:), and some provide both (e.g., 36: 2188: 2094: 1967: 1941: 1906: 1827: 1744: 1718: 1691: 1664: 1630: 1573: 1415:. CRC Press. pp. 425–488. 1367:. CRC Press. pp. 283–319. 677: 634:Public key digital certificates 439:and non-repudiation protocols. 398: 208:. Key pairs are generated with 180:In this example the message is 47:needs additional citations for 1551: 1526: 1467: 1326:. Prentice Hall. p. 165. 1313: 1250: 714:. In July 1996, mathematician 317: 268:Transport Layer Security (TLS) 13: 1: 2218: 1698:Shamir, Adi (November 1982). 1567:Lecture Notes on Cryptography 928:Elliptic-curve Diffie–Hellman 519:brute-force key search attack 512: 496: 2195:Robinson, Sara (June 2003). 850:a product of two very large 538:"knapsack packing" algorithm 7: 1648:10.1007/978-3-031-33386-6_3 1259:"Post-quantum cryptography" 1109: 1052:, EMV Certificate Authority 917:Elliptic-curve cryptography 907:Digital Signature Algorithm 900:Diffie–Hellman key exchange 888: 809:Diffie–Hellman key exchange 751:Diffie–Hellman key exchange 296:Digital Signature Algorithm 288:Diffie–Hellman key exchange 165:Diffie–Hellman key exchange 10: 2475: 2337:Christof Paar, Jan Pelzl, 1808:percy (4 September 2014). 1777:martin (30 January 2013). 1046:, and an Internet Standard 661: 555:"man-in-the-middle" attack 460:symmetric-key cryptography 454:to encrypt and exchange a 2449:Public key infrastructure 2396:Charles Babbage Institute 2359:10.1007/978-3-662-03269-5 2136:Communications of the ACM 1927:10.1080/0161-119691884933 1449:Algorithmic Number Theory 1226:. Network Working Group. 1220:R. Shirey (August 2007). 1168:Public key infrastructure 1148:Post-quantum cryptography 1127:Identity-based encryption 982:Cramer–Shoup cryptosystem 710:problem used to create a 684:The Principles of Science 590:public key infrastructure 584:Public key infrastructure 574:Internet service provider 549:Alteration of public keys 458:, which is then used by 366:public key infrastructure 71:"Public-key cryptography" 2318:. Taylor & Francis. 2081:10.1109/TIT.1976.1055638 1887:Weisstein, E.W. (2024). 1206: 1104:Off-the-Record Messaging 1076:Transport Layer Security 856:factoring large integers 755:National Security Agency 743:RSA encryption algorithm 639:man-in-the-middle attack 324:symmetric key algorithms 2459:Cryptographic protocols 2429:Public-key cryptography 2347:Public-Key Cryptography 2308:; van Oorschot, P. C.; 2102:"Asymmetric encryption" 1534:"Asymmetric encryption" 1190:Symmetric-key algorithm 1042:, an implementation of 737:In 1973, his colleague 668:history of cryptography 370:certificate authorities 194:asymmetric cryptography 190:Public-key cryptography 18:Public key cryptography 2439:Cryptographic software 2349:(2 ed.). Berlin: 2345:Salomaa, Arto (1996). 2280:; Lindell, Y. (2007). 2256:Practical Cryptography 2026:. Doubleday. pp.  1195:Threshold cryptosystem 1163:Public key fingerprint 1138:Key-agreement protocol 974:encryption algorithm ( 807:, came to be known as 781: 700: 688:William Stanley Jevons 452:key-exchange algorithm 437:time-stamping services 186: 173: 156: 147: 2226:Hirsch, Frederick J. 2159:10.1145/359340.359342 1858:Jevons, W.S. (1874). 1400:van Oorschot, Paul C. 1352:van Oorschot, Paul C. 1117:Books on cryptography 1011:McEliece cryptosystem 967:Paillier cryptosystem 848:exponentiation modulo 759: 747:Malcolm J. Williamson 692: 228:public-key encryption 198:cryptographic systems 179: 162: 153: 137: 2454:Network architecture 1444:Bernstein, Daniel J. 1179:Quantum cryptography 1082:and its predecessor 722:Classified discovery 645:Unencrypted metadata 616:and its predecessor 542:side-channel attacks 481:hybrid cryptosystems 443:Hybrid cryptosystems 326:, in which the same 304:symmetric encryption 204:and a corresponding 56:improve this article 2176:on 17 December 2008 1866:Macmillan & Co. 1712:10.1109/SFCS.1982.5 1283:10.1038/nature23461 1275:2017Natur.549..188B 1153:Pretty Good Privacy 1084:Secure Socket Layer 864:Scientific American 840:Scientific American 799:who, influenced by 493:shared connection. 286:and secrecy (e.g., 2444:Banking technology 2434:Anonymity networks 2310:Vanstone, Scott A. 2232:Apache HTTP Server 2106:IONOS Digitalguide 2046:Hellman, Martin E. 1598:10.1049/cmu2.12561 1586:IET Communications 1538:IONOS Digitalguide 1404:Vanstone, Scott A. 1396:Menezes, Alfred J. 1356:Vanstone, Scott A. 1348:Menezes, Alfred J. 875:ElGamal encryption 871:Rabin cryptosystem 860:Mathematical Games 531:ElGamal encryption 389:domain name system 354:Digital signatures 292:digital signatures 196:, is the field of 187: 174: 157: 148: 2368:978-3-662-03269-5 2297:978-1-58488-551-1 2048:(November 1976). 2042:Diffie, Whitfield 1789:on 19 August 2016 1684:978-3-642-04100-6 1658:978-3-031-33386-6 1493:10.3390/s17071517 1269:(7671): 188–194. 1174:Quantum computing 1122:GNU Privacy Guard 716:Solomon W. Golomb 712:trapdoor function 704:one-way functions 682:In his 1874 book 672:distributing keys 666:During the early 507:quantum computing 412:digital signature 328:cryptographic key 264:non-repudiability 244:digital signature 221:one-way functions 132: 131: 124: 106: 16:(Redirected from 2466: 2404:Whitfield Diffie 2380: 2329: 2301: 2273: 2242: 2240: 2238: 2212: 2211: 2201: 2192: 2186: 2185: 2183: 2181: 2175: 2169:. Archived from 2152: 2132: 2123: 2117: 2116: 2114: 2112: 2098: 2092: 2091: 2089: 2074: 2054: 2038: 2032: 2031: 2014: 2008: 2007: 1993: 1984: 1983: 1971: 1965: 1964: 1962: 1960: 1954: 1945: 1939: 1938: 1910: 1904: 1903: 1901: 1899: 1889:"Jevons' Number" 1884: 1878: 1877: 1875: 1873: 1855: 1846: 1845: 1843: 1831: 1825: 1824: 1822: 1820: 1805: 1799: 1798: 1796: 1794: 1785:. Archived from 1774: 1768: 1767: 1765: 1763: 1748: 1742: 1741: 1739: 1737: 1722: 1716: 1715: 1695: 1689: 1688: 1668: 1662: 1661: 1650: 1634: 1628: 1627: 1609: 1577: 1571: 1570: 1564: 1555: 1549: 1548: 1546: 1544: 1530: 1524: 1523: 1513: 1495: 1471: 1465: 1464: 1462: 1460: 1454: 1440: 1434: 1433: 1431: 1429: 1414: 1392: 1386: 1385: 1383: 1381: 1366: 1344: 1338: 1337: 1317: 1311: 1310: 1254: 1248: 1244: 1235: 1233:10.17487/RFC4949 1217: 1078:standardized by 813:Merkle's Puzzles 793:Whitfield Diffie 787:Public discovery 290:), some provide 284:key distribution 219:problems termed 182:digitally signed 170:symmetric cipher 127: 120: 116: 113: 107: 105: 64: 40: 32: 21: 2474: 2473: 2469: 2468: 2467: 2465: 2464: 2463: 2419: 2418: 2388: 2383: 2369: 2326: 2298: 2270: 2252:Schneier, Bruce 2248:Ferguson, Niels 2236: 2234: 2221: 2216: 2215: 2199: 2193: 2189: 2179: 2177: 2173: 2150:10.1.1.607.2677 2130: 2124: 2120: 2110: 2108: 2100: 2099: 2095: 2087: 2052: 2039: 2035: 2015: 2011: 1994: 1987: 1972: 1968: 1958: 1956: 1952: 1946: 1942: 1911: 1907: 1897: 1895: 1885: 1881: 1871: 1869: 1856: 1849: 1832: 1828: 1818: 1816: 1806: 1802: 1792: 1790: 1775: 1771: 1761: 1759: 1749: 1745: 1735: 1733: 1723: 1719: 1696: 1692: 1685: 1669: 1665: 1659: 1635: 1631: 1578: 1574: 1562: 1556: 1552: 1542: 1540: 1532: 1531: 1527: 1472: 1468: 1458: 1456: 1452: 1441: 1437: 1427: 1425: 1423: 1412: 1393: 1389: 1379: 1377: 1375: 1364: 1345: 1341: 1334: 1318: 1314: 1255: 1251: 1218: 1214: 1209: 1204: 1112: 891: 828:Leonard Adleman 789: 724: 680: 664: 647: 586: 551: 515: 499: 445: 422:Non-repudiation 405:confidentiality 401: 348:confidentiality 320: 302:). Compared to 128: 117: 111: 108: 65: 63: 53: 41: 28: 23: 22: 15: 12: 11: 5: 2472: 2462: 2461: 2456: 2451: 2446: 2441: 2436: 2431: 2417: 2416: 2411: 2400:Martin Hellman 2387: 2386:External links 2384: 2382: 2381: 2367: 2342: 2335: 2330: 2324: 2306:Menezes, A. J. 2302: 2296: 2274: 2268: 2244: 2222: 2220: 2217: 2214: 2213: 2187: 2143:(2): 120–126. 2118: 2093: 2072:10.1.1.37.9720 2065:(6): 644–654. 2033: 2009: 1985: 1966: 1955:. CryptoCellar 1940: 1905: 1879: 1847: 1826: 1800: 1769: 1743: 1717: 1690: 1683: 1663: 1657: 1629: 1592:(6): 758–773. 1572: 1550: 1525: 1466: 1435: 1421: 1387: 1373: 1339: 1332: 1312: 1249: 1246:Informational. 1211: 1210: 1208: 1205: 1203: 1202: 1197: 1192: 1187: 1181: 1176: 1171: 1165: 1160: 1155: 1150: 1145: 1140: 1135: 1130: 1124: 1119: 1113: 1111: 1108: 1107: 1106: 1101: 1096: 1091: 1086: 1073: 1063: 1058: 1053: 1047: 1037: 1026: 1025: 1014: 1013: 1008: 1003: 991: 990: 984: 979: 969: 964: 957: 956: 955: 945: 931: 925: 914: 909: 903: 890: 887: 836:Martin Gardner 830:, all then at 797:Martin Hellman 788: 785: 778:Ralph Benjamin 739:Clifford Cocks 728:James H. Ellis 723: 720: 679: 676: 663: 660: 646: 643: 585: 582: 550: 547: 523:Claude Shannon 514: 511: 498: 495: 484:. The initial 444: 441: 416:authentication 400: 397: 358: 357: 351: 333:secure channel 319: 316: 130: 129: 44: 42: 35: 26: 9: 6: 4: 3: 2: 2471: 2460: 2457: 2455: 2452: 2450: 2447: 2445: 2442: 2440: 2437: 2435: 2432: 2430: 2427: 2426: 2424: 2415: 2412: 2409: 2405: 2401: 2397: 2393: 2390: 2389: 2378: 2374: 2370: 2364: 2360: 2356: 2352: 2348: 2343: 2340: 2336: 2334: 2331: 2327: 2325:0-8493-8523-7 2321: 2317: 2316: 2311: 2307: 2303: 2299: 2293: 2289: 2285: 2284: 2279: 2275: 2271: 2269:0-471-22357-3 2265: 2261: 2257: 2253: 2249: 2245: 2233: 2229: 2224: 2223: 2209: 2205: 2198: 2191: 2172: 2168: 2164: 2160: 2156: 2151: 2146: 2142: 2138: 2137: 2129: 2122: 2107: 2103: 2097: 2086: 2082: 2078: 2073: 2068: 2064: 2060: 2059: 2051: 2047: 2043: 2037: 2029: 2025: 2024: 2023:The Code Book 2019: 2013: 2005: 2004: 1999: 1992: 1990: 1981: 1980:The Telegraph 1977: 1970: 1951: 1944: 1936: 1932: 1928: 1924: 1920: 1916: 1909: 1894: 1890: 1883: 1867: 1863: 1862: 1854: 1852: 1842: 1837: 1830: 1815: 1811: 1804: 1788: 1784: 1780: 1773: 1758: 1754: 1747: 1732: 1728: 1721: 1713: 1709: 1705: 1701: 1694: 1686: 1680: 1676: 1675: 1667: 1660: 1654: 1649: 1644: 1640: 1633: 1625: 1621: 1617: 1613: 1608: 1603: 1599: 1595: 1591: 1587: 1583: 1576: 1568: 1561: 1554: 1539: 1535: 1529: 1521: 1517: 1512: 1507: 1503: 1499: 1494: 1489: 1485: 1481: 1477: 1470: 1451: 1450: 1445: 1439: 1424: 1422:0-8493-8523-7 1418: 1411: 1410: 1405: 1401: 1397: 1391: 1376: 1374:0-8493-8523-7 1370: 1363: 1362: 1357: 1353: 1349: 1343: 1335: 1333:9780138690175 1329: 1325: 1324: 1316: 1308: 1304: 1300: 1296: 1292: 1288: 1284: 1280: 1276: 1272: 1268: 1264: 1260: 1253: 1247: 1242: 1239: 1234: 1229: 1225: 1224: 1216: 1212: 1201: 1198: 1196: 1193: 1191: 1188: 1185: 1182: 1180: 1177: 1175: 1172: 1169: 1166: 1164: 1161: 1159: 1156: 1154: 1151: 1149: 1146: 1144: 1143:PGP word list 1141: 1139: 1136: 1134: 1131: 1128: 1125: 1123: 1120: 1118: 1115: 1114: 1105: 1102: 1100: 1097: 1095: 1092: 1090: 1087: 1085: 1081: 1077: 1074: 1071: 1067: 1064: 1062: 1059: 1057: 1054: 1051: 1048: 1045: 1041: 1038: 1036: 1033: 1032: 1031: 1030: 1024: 1021: 1020: 1019: 1018: 1012: 1009: 1007: 1004: 1001: 998: 997: 996: 995: 988: 985: 983: 980: 977: 973: 970: 968: 965: 962: 958: 953: 949: 946: 943: 939: 935: 932: 929: 926: 923: 920: 919: 918: 915: 913: 910: 908: 904: 901: 898: 897: 896: 895: 886: 884: 880: 876: 872: 867: 865: 861: 857: 853: 849: 845: 841: 837: 833: 829: 825: 821: 816: 814: 810: 806: 802: 798: 794: 784: 780: 779: 774: 772: 768: 764: 758: 756: 752: 748: 744: 740: 735: 733: 729: 719: 717: 713: 709: 708:factorization 705: 699: 697: 691: 689: 685: 675: 673: 669: 659: 655: 652: 642: 640: 635: 630: 625: 623: 619: 615: 610: 607: 603: 597: 595: 591: 581: 577: 575: 571: 565: 563: 558: 556: 546: 543: 539: 534: 532: 528: 524: 520: 510: 508: 503: 494: 491: 487: 483: 482: 477: 473: 469: 465: 464:symmetric key 461: 457: 456:symmetric key 453: 450: 440: 438: 434: 430: 425: 423: 419: 417: 413: 408: 406: 396: 394: 390: 386: 382: 377: 375: 371: 367: 362: 355: 352: 350:of a message. 349: 344: 343: 342: 339: 336: 334: 329: 325: 315: 313: 309: 305: 301: 297: 293: 289: 285: 281: 277: 273: 269: 265: 261: 260:cryptosystems 256: 252: 250: 246: 245: 239: 235: 233: 229: 224: 222: 218: 214: 211: 210:cryptographic 207: 203: 199: 195: 191: 183: 178: 171: 166: 161: 152: 145: 141: 136: 126: 123: 115: 104: 101: 97: 94: 90: 87: 83: 80: 76: 73: â€“  72: 68: 67:Find sources: 61: 57: 51: 50: 45:This article 43: 39: 34: 33: 30: 19: 2408:Ralph Merkle 2346: 2314: 2282: 2255: 2235:. Retrieved 2231: 2207: 2203: 2190: 2178:. Retrieved 2171:the original 2140: 2134: 2121: 2109:. Retrieved 2105: 2096: 2062: 2056: 2036: 2022: 2018:Singh, Simon 2012: 2001: 1979: 1969: 1957:. Retrieved 1943: 1918: 1914: 1908: 1896:. Retrieved 1882: 1870:. Retrieved 1860: 1829: 1817:. Retrieved 1813: 1803: 1791:. Retrieved 1787:the original 1782: 1772: 1760:. Retrieved 1756: 1746: 1734:. Retrieved 1730: 1720: 1703: 1693: 1677:. Springer. 1673: 1666: 1638: 1632: 1589: 1585: 1575: 1566: 1553: 1541:. Retrieved 1537: 1528: 1483: 1479: 1469: 1457:. Retrieved 1448: 1438: 1426:. Retrieved 1408: 1390: 1378:. Retrieved 1360: 1342: 1322: 1315: 1266: 1262: 1252: 1245: 1222: 1215: 1200:Web of trust 1184:Secure Shell 1028: 1027: 1016: 1015: 1002:cryptosystem 993: 992: 893: 892: 868: 817: 801:Ralph Merkle 790: 782: 775: 760: 736: 725: 701: 693: 683: 681: 678:Anticipation 665: 656: 648: 626: 611: 605: 602:Web browsers 598: 587: 578: 566: 559: 552: 535: 516: 504: 500: 489: 485: 479: 463: 455: 448: 446: 429:digital cash 426: 420: 409: 402: 399:Applications 381:web of trust 378: 363: 359: 340: 337: 321: 312:Secure Shell 257: 253: 248: 242: 240: 236: 231: 227: 225: 217:mathematical 205: 201: 193: 189: 188: 118: 112:January 2024 109: 99: 92: 85: 78: 66: 54:Please help 49:verification 46: 29: 2180:15 November 1915:Cryptologia 1868:p. 141 1706:: 145–152. 1607:10016/37141 1486:(7): 1517. 1068:, a secure 1000:NTRUEncrypt 954:(ECDH/EdDH) 763:Berners-Lee 391:(DNS). The 318:Description 206:private key 2423:Categories 2219:References 1959:18 January 1921:(3): 243. 1898:18 January 1872:18 January 1133:Key escrow 963:techniques 824:Adi Shamir 820:Ron Rivest 696:8616460799 606:bona fides 513:Algorithms 497:Weaknesses 486:asymmetric 474:, and the 449:asymmetric 232:ciphertext 213:algorithms 202:public key 82:newspapers 2288:CRC Press 2278:Katz, Jon 2204:SIAM News 2145:CiteSeerX 2067:CiteSeerX 1935:205488749 1893:MathWorld 1841:1411.6409 1814:GreatFire 1783:GreatFire 1624:255650398 1616:1751-8628 1502:1424-8220 1459:8 October 1428:8 October 1380:8 October 1291:0028-0836 1158:Pseudonym 726:In 1970, 629:hierarchy 490:symmetric 249:signature 215:based on 185:modified. 2377:24751345 2351:Springer 2312:(1997). 2254:(2003). 2237:17 April 2085:Archived 2020:(1999). 1520:28654006 1299:28905891 1110:See also 1072:protocol 959:Various 902:protocol 889:Examples 651:metadata 570:Internet 562:sniffing 2353:. 275. 2167:2873616 1819:26 June 1793:27 June 1762:26 June 1757:UpGuard 1736:26 June 1731:UpGuard 1511:5551094 1480:Sensors 1307:4446249 1271:Bibcode 1099:Bitcoin 1044:OpenPGP 934:Ed25519 924:(ECDSA) 912:ElGamal 771:Arpanet 662:History 476:SSL/TLS 294:(e.g., 163:In the 96:scholar 2375:  2365:  2322:  2294:  2266:  2165:  2147:  2111:9 June 2069:  1933:  1681:  1655:  1622:  1614:  1543:2 June 1518:  1508:  1500:  1419:  1371:  1330:  1305:  1297:  1289:  1263:Nature 1035:S/MIME 976:PKCS#1 948:X25519 930:(ECDH) 852:primes 690:wrote: 594:revoke 276:S/MIME 155:other. 140:random 98:  91:  84:  77:  69:  2373:S2CID 2260:Wiley 2200:(PDF) 2174:(PDF) 2163:S2CID 2131:(PDF) 2088:(PDF) 2053:(PDF) 2030:–292. 2003:ZDNet 1953:(PDF) 1931:S2CID 1836:arXiv 1620:S2CID 1563:(PDF) 1453:(PDF) 1413:(PDF) 1365:(PDF) 1303:S2CID 1207:Notes 1186:(SSH) 1170:(PKI) 1129:(IBE) 1056:IPsec 1006:Kyber 942:EdDSA 938:Ed448 622:HTTPS 241:In a 226:In a 192:, or 103:JSTOR 89:books 2406:and 2363:ISBN 2320:ISBN 2292:ISBN 2264:ISBN 2239:2013 2210:(5). 2182:2019 2113:2022 1961:2024 1900:2024 1874:2024 1821:2020 1795:2015 1764:2020 1738:2020 1679:ISBN 1653:ISBN 1612:ISSN 1545:2022 1516:PMID 1498:ISSN 1461:2022 1430:2022 1417:ISBN 1382:2022 1369:ISBN 1328:ISBN 1295:PMID 1287:ISSN 1241:4949 1089:SILC 1080:IETF 1070:VoIP 1066:ZRTP 952:X448 950:and 936:and 881:and 826:and 795:and 767:CERN 529:and 393:DKIM 278:and 144:keys 75:news 2355:doi 2155:doi 2077:doi 2028:279 1923:doi 1708:doi 1643:doi 1602:hdl 1594:doi 1506:PMC 1488:doi 1279:doi 1267:549 1238:RFC 1228:doi 1094:SSH 1061:PGP 1050:EMV 1040:GPG 987:YAK 972:RSA 883:ECC 879:DSA 844:RSA 838:'s 832:MIT 624:). 618:SSL 614:TLS 527:RSA 472:SSH 468:PGP 385:PGP 379:A " 374:TLS 308:TLS 300:RSA 280:PGP 272:SSH 58:by 2425:: 2394:, 2371:. 2361:. 2290:. 2286:. 2262:. 2258:. 2250:; 2230:. 2208:36 2206:. 2202:. 2161:. 2153:. 2141:21 2139:. 2133:. 2104:. 2083:. 2075:. 2063:22 2061:. 2055:. 2044:; 2000:. 1988:^ 1978:. 1929:. 1919:20 1917:. 1891:. 1864:. 1850:^ 1812:. 1781:. 1755:. 1729:. 1702:. 1651:, 1618:. 1610:. 1600:. 1590:17 1588:. 1584:. 1565:. 1536:. 1514:. 1504:. 1496:. 1484:17 1482:. 1478:. 1402:; 1398:; 1354:; 1350:; 1301:. 1293:. 1285:. 1277:. 1265:. 1261:. 1236:. 885:. 877:, 873:, 866:. 822:, 686:, 674:. 470:, 435:, 431:, 418:. 364:A 310:, 274:, 270:, 2379:. 2357:: 2328:. 2300:. 2272:. 2241:. 2184:. 2157:: 2115:. 2079:: 2006:. 1982:. 1963:. 1937:. 1925:: 1902:. 1876:. 1844:. 1838:: 1823:. 1797:. 1766:. 1740:. 1714:. 1710:: 1687:. 1645:: 1626:. 1604:: 1596:: 1569:. 1547:. 1522:. 1490:: 1463:. 1432:. 1384:. 1336:. 1309:. 1281:: 1273:: 1243:. 1230:: 978:) 944:) 940:( 776:— 637:" 125:) 119:( 114:) 110:( 100:· 93:· 86:· 79:· 52:. 20:)

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