Your browser does not fully support modern features. Please upgrade for a smoother experience.
Submitted Successfully!
Thank you for your contribution! You can also upload a video entry or images related to this topic. For video creation, please contact our Academic Video Service.
Version Summary Created by Modification Content Size Created at Operation
1 handwiki Dean Liu -- 7857 2022-11-28 01:45:14

Video Upload Options

We provide professional Academic Video Service to translate complex research into visually appealing presentations. Would you like to try it?
Cite
If you have any further questions, please contact Encyclopedia Editorial Office.
HandWiki. Cryptography. Encyclopedia. Available online: https://encyclopedia.pub/entry/36775 (accessed on 14 September 2026).
HandWiki. Cryptography. Encyclopedia. Available at: https://encyclopedia.pub/entry/36775. Accessed September 14, 2026.
HandWiki. "Cryptography" Encyclopedia, https://encyclopedia.pub/entry/36775 (accessed September 14, 2026).
HandWiki. (2022, November 28). Cryptography. In Encyclopedia. https://encyclopedia.pub/entry/36775
HandWiki. "Cryptography." Encyclopedia. Web. 28 November, 2022.
Cryptography
Edit

Cryptography, or cryptology (from Ancient Greek: "hidden, secret"; and γράφειν graphein, "to write", or -λογία -logia, "study", respectively), is the practice and study of techniques for secure communication in the presence of adversarial behavior. More generally, cryptography is about constructing and analyzing protocols that prevent third parties or the public from reading private messages. Modern cryptography exists at the intersection of the disciplines of mathematics, computer science, information security, electrical engineering, digital signal processing, physics, and others. Core concepts related to information security (data confidentiality, data integrity, authentication, and non-repudiation) are also central to cryptography. Practical applications of cryptography include electronic commerce, chip-based payment cards, digital currencies, computer passwords, and military communications. Cryptography prior to the modern age was effectively synonymous with encryption, converting readable information (plaintext) to unintelligible nonsense text (ciphertext), which can only be read by reversing the process (decryption). The sender of an encrypted (coded) message shares the decryption (decoding) technique only with intended recipients to preclude access from adversaries. The cryptography literature often uses the names "Alice" (or "A") for the sender, "Bob" (or "B") for the intended recipient, and "Eve" (or "E") for the eavesdropping adversary. Since the development of rotor cipher machines in World War I and the advent of computers in World War II, cryptography methods have become increasingly complex and their applications more varied. Modern cryptography is heavily based on mathematical theory and computer science practice; cryptographic algorithms are designed around computational hardness assumptions, making such algorithms hard to break in actual practice by any adversary. While it is theoretically possible to break into a well-designed system, it is infeasible in actual practice to do so. Such schemes, if well designed, are therefore termed "computationally secure"; theoretical advances (e.g., improvements in integer factorization algorithms) and faster computing technology require these designs to be continually reevaluated, and if necessary, adapted. Information-theoretically secure schemes that cannot be broken even with unlimited computing power, such as the one-time pad, are much more difficult to use in practice than the best theoretically breakable, but computationally secure, schemes. The growth of cryptographic technology has raised a number of legal issues in the Information Age. Cryptography's potential for use as a tool for espionage and sedition has led many governments to classify it as a weapon and to limit or even prohibit its use and export. In some jurisdictions where the use of cryptography is legal, laws permit investigators to compel the disclosure of encryption keys for documents relevant to an investigation. Cryptography also plays a major role in digital rights management and copyright infringement disputes in regard to digital media.

mathematical theory computational hardness computing technology

References

  1. Biggs, Norman (2008). Codes: An introduction to Information Communication and Cryptography. Springer. p. 171. https://archive.org/details/codesintroductio00bigg_911. 
  2. Whalen, Terence (1994). "The Code for Gold: Edgar Allan Poe and Cryptography". Representations (University of California Press) 46 (46): 35–57. doi:10.2307/2928778.  https://dx.doi.org/10.2307%2F2928778
  3. Lua error: Internal error: The interpreter exited with status 1.
  4. Kahn, David (1967). The Codebreakers. ISBN 978-0-684-83130-5. 
  5. "An Introduction to Modern Cryptosystems". https://www.giac.org/paper/gsec/2604/introduction-modern-cryptosystems/104482. 
  6. Sharbaf, M.S. (2011-11-01). "Quantum cryptography: An emerging technology in network security". 2011 IEEE International Conference on Technologies for Homeland Security (HST): 13–19. doi:10.1109/THS.2011.6107841. ISBN 978-1-4577-1376-7.  https://dx.doi.org/10.1109%2FTHS.2011.6107841
  7. "cryptology | Britannica" (in en). https://www.britannica.com/topic/cryptology. 
  8. Oded Goldreich, Foundations of Cryptography, Volume 1: Basic Tools, Cambridge University Press, 2001, ISBN:0-521-79172-3
  9. "Cryptology (definition)". Merriam-Webster's Collegiate Dictionary (11th ed.). Merriam-Webster. http://www.merriam-webster.com/dictionary/cryptology. Retrieved 26 March 2015. 
  10. Shirey, Rob (May 2000). Internet Security Glossary. doi:10.17487/RFC2828. https://tools.ietf.org/html/rfc2828. Retrieved 26 March 2015. 
  11. Saltzman, Benjamin A. (2018-10-01). "Vt hkskdkxt: Early Medieval Cryptography, Textual Errors, and Scribal Agency" (in en). Speculum 93 (4): 975–1009. doi:10.1086/698861. ISSN 0038-7134. https://www.journals.uchicago.edu/doi/10.1086/698861. 
  12. I︠A︡shchenko, V.V. (2002). Cryptography: an introduction. AMS Bookstore. p. 6. ISBN 978-0-8218-2986-8. https://books.google.com/books?id=cH-NGrpcIMcC&pg=PA6. 
  13. electricpulp.com. "CODES – Encyclopaedia Iranica". http://www.iranicaonline.org/articles/codes-romuz-sg. 
  14. Kahn, David (1996). The Codebreakers: The Comprehensive History of Secret Communication from Ancient Times to the Internet. Simon and Schuster. ISBN 9781439103555. https://books.google.com/books?id=3S8rhOEmDIIC&q=david+kahn+the+codebreakers. 
  15. Broemeling, Lyle D. (1 November 2011). "An Account of Early Statistical Inference in Arab Cryptology". The American Statistician 65 (4): 255–257. doi:10.1198/tas.2011.10191.  https://dx.doi.org/10.1198%2Ftas.2011.10191
  16. Singh, Simon (2000). The Code Book. New York: Anchor Books. pp. 14–20. ISBN 978-0-385-49532-5. 
  17. Al-Kadi, Ibrahim A. (April 1992). "The origins of cryptology: The Arab contributions". Cryptologia 16 (2): 97–126. doi:10.1080/0161-119291866801.  https://dx.doi.org/10.1080%2F0161-119291866801
  18. Schrödel, Tobias (October 2008). "Breaking Short Vigenère Ciphers". Cryptologia 32 (4): 334–337. doi:10.1080/01611190802336097.  https://dx.doi.org/10.1080%2F01611190802336097
  19. Hakim, Joy (1995). A History of US: War, Peace and all that Jazz. New York: Oxford University Press. ISBN 978-0-19-509514-2. 
  20. Gannon, James (2001). Stealing Secrets, Telling Lies: How Spies and Codebreakers Helped Shape the Twentieth Century. Washington, D.C.: Brassey's. ISBN 978-1-57488-367-1. https://archive.org/details/stealingsecretst00gann. 
  21. "The Legacy of DES - Schneier on Security". https://www.schneier.com/blog/archives/2004/10/the_legacy_of_d.html. 
  22. Diffie, Whitfield; Hellman, Martin (November 1976). "New Directions in Cryptography". IEEE Transactions on Information Theory IT-22 (6): 644–654. doi:10.1109/tit.1976.1055638. http://www-ee.stanford.edu/~hellman/publications/24.pdf. 
  23. Singh, Simon (1999). The Code Book: The Science of Secrecy From Ancient Egypt To Quantum Cryptography (First Anchor Books ed.). New York: Anchor Books. pp. 278. ISBN 978-0-385-49532-5. https://archive.org/details/codebook00simo/page/278. 
  24. Cryptography: Theory and Practice, Third Edition (Discrete Mathematics and Its Applications), 2005, by Douglas R. Stinson, Chapman and Hall/CRC
  25. Blaze, Matt; Diffie, Whitefield; Rivest, Ronald L.; Schneier, Bruce; Shimomura, Tsutomu; Thompson, Eric; Wiener, Michael (January 1996). "Minimal key lengths for symmetric ciphers to provide adequate commercial security". Fortify. http://www.fortify.net/related/cryptographers.html. 
  26. Menezes, A.J.; van Oorschot, P.C.; Vanstone, S.A. (1997). Handbook of Applied Cryptography. ISBN 978-0-8493-8523-0. https://archive.org/details/handbookofapplie0000mene. 
  27. Diffie, W.; Hellman, M. (1 September 2006). "New directions in cryptography". IEEE Transactions on Information Theory 22 (6): 644–654. doi:10.1109/TIT.1976.1055638. https://dl.acm.org/doi/10.1109/TIT.1976.1055638. 
  28. "FIPS PUB 197: The official Advanced Encryption Standard". National Institute of Standards and Technology. http://www.csrc.nist.gov/publications/fips/fips197/fips-197.pdf. 
  29. "NCUA letter to credit unions". July 2004. http://www.ncua.gov/Resources/Documents/LCU2004-09.pdf. 
  30. Finney, Hal; Thayer, Rodney L.; Donnerhacke, Lutz; Callas, Jon (November 1998). Open PGP Message Format. doi:10.17487/RFC2440. https://tools.ietf.org/html/rfc2440. Retrieved 26 March 2015. 
  31. Golen, Pawel (19 July 2002). "SSH". http://www.windowsecurity.com/articles/SSH.html. 
  32. Schneier, Bruce (1996). Applied Cryptography (2nd ed.). John Wiley & Sons. ISBN 978-0-471-11709-4. https://archive.org/details/Applied_Cryptography_2nd_ed._B._Schneier. 
  33. Paar, Christof (2009). Understanding cryptography : a textbook for students and practitioners. Jan Pelzl. Berlin: Springer. p. 123. ISBN 978-3-642-04101-3. OCLC 567365751. https://www.worldcat.org/oclc/567365751. 
  34. Bernstein, Daniel J.; Lange, Tanja (2017-09-14). "Post-quantum cryptography" (in en). Nature 549 (7671): 188–194. doi:10.1038/nature23461. ISSN 0028-0836. PMID 28905891. Bibcode: 2017Natur.549..188B. http://www.nature.com/articles/nature23461. 
  35. "Notices". Federal Register 72 (212). 2 November 2007. "Archived copy". http://csrc.nist.gov/groups/ST/hash/documents/FR_Notice_Nov07.pdf. 
  36. "NIST Selects Winner of Secure Hash Algorithm (SHA-3) Competition". Nist (National Institute of Standards and Technology). October 2, 2012. https://www.nist.gov/itl/csd/sha-100212.cfm. Retrieved 26 March 2015. 
  37. Diffie, Whitfield; Hellman, Martin (8 June 1976). "Multi-user cryptographic techniques". AFIPS Proceedings 45: 109–112. doi:10.1145/1499799.1499815.  https://dx.doi.org/10.1145%2F1499799.1499815
  38. Ralph Merkle was working on similar ideas at the time and encountered publication delays, and Hellman has suggested that the term used should be Diffie–Hellman–Merkle aysmmetric key cryptography.
  39. Kahn, David (Fall 1979). "Cryptology Goes Public". Foreign Affairs 58 (1): 141–159. doi:10.2307/20040343.  https://dx.doi.org/10.2307%2F20040343
  40. "Using Client-Certificate based authentication with NGINX on Ubuntu - SSLTrust". https://www.ssltrust.com.au/help/setup-guides/client-certificate-authentication. 
  41. Rivest, Ronald L.; Shamir, A.; Adleman, L. (1978). "A Method for Obtaining Digital Signatures and Public-Key Cryptosystems". Communications of the ACM 21 (2): 120–126. doi:10.1145/359340.359342. "Archived copy". http://theory.lcs.mit.edu/~rivest/rsapaper.pdf. Previously released as an MIT "Technical Memo" in April 1977, and published in Martin Gardner's Scientific American Mathematical recreations column
  42. Wayner, Peter (24 December 1997). "British Document Outlines Early Encryption Discovery". The New York Times. https://www.nytimes.com/library/cyber/week/122497encrypt.html. 
  43. Cocks, Clifford (20 November 1973). "A Note on 'Non-Secret Encryption'". CESG Research Report. http://www.fi.muni.cz/usr/matyas/lecture/paper2.pdf. 
  44. Singh, Simon (1999). The Code Book. Doubleday. pp. 279–292. ISBN 9780385495318. https://archive.org/details/codebookevolutio00sing. 
  45. Shannon, Claude; Weaver, Warren (1963). The Mathematical Theory of Communication. University of Illinois Press. ISBN 978-0-252-72548-7. 
  46. "An Example of a Man-in-the-middle Attack Against Server Authenticated SSL-sessions". http://www8.cs.umu.se/education/examina/Rapporter/MattiasEriksson.pdf. 
  47. Junod, Pascal (2001). On the Complexity of Matsui's Attack. Lecture Notes in Computer Science. 2259. 199–211. doi:10.1007/3-540-45537-X_16. ISBN 978-3-540-43066-7. http://citeseer.ist.psu.edu/cache/papers/cs/22094/http:zSzzSzeprint.iacr.orgzSz2001zSz056.pdf/junod01complexity.pdf. 
  48. Song, Dawn; Wagner, David A.; Tian, Xuqing (2001). "Timing Analysis of Keystrokes and Timing Attacks on SSH". Tenth USENIX Security Symposium. http://citeseer.ist.psu.edu/cache/papers/cs/22094/http:zSzzSzeprint.iacr.orgzSz2001zSz056.pdf/junod01complexity.pdf. 
  49. Brands, S. (1994). "Untraceable Off-line Cash in Wallet with Observers". Untraceable Off-line Cash in Wallets with Observers. Lecture Notes in Computer Science. 773. 302–318. doi:10.1007/3-540-48329-2_26. ISBN 978-3-540-57766-9. http://ftp.se.kde.org/pub/security/docs/ecash/crypto93.ps.gz. 
  50. Babai, László (1985). "Trading group theory for randomness". Proceedings of the seventeenth annual ACM symposium on Theory of computing - STOC '85. Stoc '85. 421–429. doi:10.1145/22145.22192. ISBN 978-0-89791-151-1. http://portal.acm.org/citation.cfm?id=22192. 
  51. Goldwasser, S.; Micali, S.; Rackoff, C. (1989). "The Knowledge Complexity of Interactive Proof Systems". SIAM Journal on Computing 18 (1): 186–208. doi:10.1137/0218012.  https://dx.doi.org/10.1137%2F0218012
  52. Blakley, G. (June 1979). "Safeguarding cryptographic keys". Proceedings of AFIPS 1979 48: 313–317. 
  53. Shamir, A. (1979). "How to share a secret". Communications of the ACM 22 (11): 612–613. doi:10.1145/359168.359176.  https://dx.doi.org/10.1145%2F359168.359176
  54. Gunathilake, Nilupulee A.; Al-Dubai, Ahmed; Buchana, William J. (2020-11-02). "Recent Advances and Trends in Lightweight Cryptography for IoT Security". 2020 16th International Conference on Network and Service Management (CNSM) (Izmir, Turkey: IEEE): 1–5. doi:10.23919/CNSM50824.2020.9269083. ISBN 978-3-903176-31-7. https://ieeexplore.ieee.org/document/9269083. 
  55. Thakor, Vishal A.; Razzaque, Mohammad Abdur; Khandaker, Muhammad R. A. (2021). "Lightweight Cryptography Algorithms for Resource-Constrained IoT Devices: A Review, Comparison and Research Opportunities". IEEE Access 9: 28177–28193. doi:10.1109/ACCESS.2021.3052867. ISSN 2169-3536.  https://dx.doi.org/10.1109%2FACCESS.2021.3052867
  56. Cohen, Fred (1995). "2.4 - Applications of Cryptography". http://all.net/edu/curr/ip/Chap2-4.html. 
  57. "4 Common Encryption Methods to Shield Sensitive Data From Prying Eyes" (in en). https://www.getapp.com/resources/common-encryption-methods/. 
  58. Chamberlain, Austin (12 March 2017). "Applications of Cryptography | UCL Risky Business". https://blogs.ucl.ac.uk/infosec/2017/03/12/applications-of-cryptography/. 
  59. "Crypto FAQ: What is cryptocurrency?" (in en). https://cryptocurrencyworks.com/faq//faq/what-is-cryptocurrency.html. 
  60. "Crypto FAQ: What is cryptoeconomics & how does it work?". https://cryptoeconworks.com/faq/what-is-cryptoeconomics.html. 
  61. Ranger, Steve (24 March 2015). "The undercover war on your internet secrets: How online surveillance cracked our trust in the web". TechRepublic. http://www.techrepublic.com/article/the-undercover-war-on-your-internet-secrets-how-online-surveillance-cracked-our-trust-in-the-web/. 
  62. "Overview per country". February 2013. http://www.cryptolaw.org/cls2.htm. 
  63. "6.5.1 What Are the Cryptographic Policies of Some Countries?". RSA Laboratories. http://www.emc.com/emc-plus/rsa-labs/standards-initiatives/cryptographic-policies-countries.htm. 
  64. Rosenoer, Jonathan (1995). "Cryptography & Speech". "Archived copy". http://www.cyberlaw.com/cylw1095.html. 
  65. "Case Closed on Zimmermann PGP Investigation". 14 February 1996. http://www.ieee-security.org/Cipher/Newsbriefs/1996/960214.zimmerman.html. 
  66. Levy, Steven (2001). Crypto: How the Code Rebels Beat the Government—Saving Privacy in the Digital Age. Penguin Books. p. 56. ISBN 978-0-14-024432-8. OCLC 244148644.  http://www.worldcat.org/oclc/244148644
  67. "Bernstein v USDOJ". United States Court of Appeals for the Ninth Circuit. 6 May 1999. http://www.epic.org/crypto/export_controls/bernstein_decision_9_cir.html. 
  68. "Dual-use List – Category 5 – Part 2 – "Information Security"" (PDF). https://www.bis.doc.gov/index.php/documents/regulations-docs/445-category-5-part-2-information-security/file. 
  69. ".4 United States Cryptography Export/Import Laws". http://www.emc.com/emc-plus/rsa-labs/standards-initiatives/united-states-cryptography-export-import.htm. 
  70. Schneier, Bruce (15 June 2000). "The Data Encryption Standard (DES)". http://www.schneier.com/crypto-gram-0006.html#DES. 
  71. Coppersmith, D. (May 1994). "The Data Encryption Standard (DES) and its strength against attacks" (PDF). IBM Journal of Research and Development 38 (3): 243–250. doi:10.1147/rd.383.0243. http://domino.watson.ibm.com/tchjr/journalindex.nsf/0/94f78816c77fc77885256bfa0067fb98?OpenDocument. Retrieved 26 March 2015. 
  72. Biham, E.; Shamir, A. (1991). "Differential cryptanalysis of DES-like cryptosystems". Journal of Cryptology 4 (1): 3–72. doi:10.1007/bf00630563.  https://dx.doi.org/10.1007%2Fbf00630563
  73. "The Digital Millennium Copyright Act of 1998". http://www.copyright.gov/legislation/dmca.pdf. 
  74. Ferguson, Niels (15 August 2001). "Censorship in action: why I don't publish my HDCP results". http://www.macfergus.com/niels/dmca/cia.html. 
  75. Schneier, Bruce (2001-08-06). "Arrest of Computer Researcher Is Arrest of First Amendment Rights". InternetWeek. https://www.schneier.com/essays/archives/2001/08/arrest_of_computer_r.html. 
  76. Doctorow, Cory (2 May 2007). "Digg users revolt over AACS key". http://boingboing.net/2007/05/02/digg-users-revolt-ov.html. 
  77. "UK Data Encryption Disclosure Law Takes Effect". 1 October 2007. http://www.pcworld.com/article/137881/uk_data_encryption_disclosure_law_takes_effect.html. 
  78. Williams, Christopher (11 August 2009). "Two convicted for refusal to decrypt data". https://www.theregister.co.uk/2009/08/11/ripa_iii_figures/. 
  79. Williams, Christopher (24 November 2009). "UK jails schizophrenic for refusal to decrypt files". https://www.theregister.co.uk/2009/11/24/ripa_jfl/. 
  80. Ingold, John (January 4, 2012). "Password case reframes Fifth Amendment rights in context of digital world". The Denver Post. http://www.denverpost.com/news/ci_19669803. 
  81. Leyden, John (13 July 2011). "US court test for rights not to hand over crypto keys". https://www.theregister.co.uk/2011/07/13/eff_piles_in_against_forced_decryption/. 
  82. "Order Granting Application under the All Writs Act Requiring Defendant Fricosu to Assist in the Execution of Previously Issued Search Warrants". United States District Court for the District of Colorado. https://www.wired.com/images_blogs/threatlevel/2012/01/decrypt.pdf. 
More
Upload a video for this entry
Information
Subjects: Others
Contributor MDPI registered users' name will be linked to their SciProfiles pages. To register with us, please refer to https://encyclopedia.pub/register :
View Times: 5.8K
Entry Collection: HandWiki
Revision: 1 time (View History)
Update Date: 28 Nov 2022
Notice
You are not a member of the advisory board for this topic. If you want to update advisory board member profile, please contact office@encyclopedia.pub.
OK
Confirm
Only members of the Encyclopedia advisory board for this topic are allowed to note entries. Would you like to become an advisory board member of the Encyclopedia?
Yes
No
${ textCharacter }/${ maxCharacter }
Submit
Cancel
There is no comment~
${ textCharacter }/${ maxCharacter }
Submit
Cancel
${ selectedItem.replyTextCharacter }/${ selectedItem.replyMaxCharacter }
Submit
Cancel
Confirm
Are you sure to Delete?
Yes No
Academic Video Service