암호학

개요

• 암호학은 정보를 의도하지 않은 수신자가 이해할 수 없는 형태로 변환하여 정보를 안전하게 유지하는 과학이다.
• 암호학은 현대의 통신환경에서 필수적이다.
• 공개 키 암호화는 모든 시민에게 강력한 암호화를 사용할 수 있게 해주는 기술이다.

메모

• Elias, Yara, Kristin E. Lauter, Ekin Ozman, and Katherine E. Stange. “Ring-LWE Cryptography for the Number Theorist.” arXiv:1508.01375 [cs, Math], August 6, 2015. http://arxiv.org/abs/1508.01375.

노트

• In all cases, cryptography, the coding enabling information to be kept secret, was flawed or missing.
• For years online security has focused on hard technical problems: Fixing software bugs or concealing data with cryptography.
• When you hear the word "cryptography," your brain probably jumps to someone sitting in a dark room staring at lines of code.
• Secret key cryptography uses one key across both the sending encryption and the receiver's decryption.
• Public Key Cryptography allows for the use of two keys, which are different for the sender and receiver.
• Drawing back to the question at hand, what is cryptography, the answer is fairly simple.
• Asymmetric encryption (or public-key cryptography) uses a separate key for encryption and decryption.
• Today, cryptography is used to protect digital data.
• An example of basic cryptography is a encrypted message in which letters are replaced with other characters.
• Therefore, modern cryptography involves developing encryption methods that are difficult for even supercomputers to break.
• The OECD Recommendation Concerning Guidelines for Cryptography Policy were adopted on 27 March 1997.
• However, the widespread use of cryptography raises a number of important issues.
• Traditionally, cryptography was most often used only by governments.
• Effective cryptography is an essential tool in a network environment for addressing these concerns.
• Cryptography uses two main styles or forms of encrypting data; symmetrical and asymmetrical.
• A key tool to secure the confidentiality of electronic communications is encryption or cryptography.
• In other words cryptography can be used as an electronic signature.
• Public-key cryptography is typically based on mathematical problems that are relatively easy to perform but cannot be easily reversed.
• "The Joy of Cryptography" is a silly title, but all the sensible titles were already taken.
• It was at least better than "You Can't Spell Cryptography without Cry".
• Cryptography is the art and science of keeping information secure from unintended audiences, of encrypting it.
• Public key cryptography adds a very significant benefit - it can serve to authenticate a source (e.g. a digital signature).
• Public key cryptography was invented by Whitfield Diffie and Martin Hellman in 1975.
• Provides a Cryptography Next Generation (CNG) implementation of the Elliptic Curve Diffie-Hellman (ECDH) algorithm.
• TripleDESCng Provides a Cryptography Next Generation (CNG) implementation of the Triple Data Encryption Standard (3DES) algorithm.
• The second phase, the mechanization of cryptography, began shortly after World War I and continues even today.
• It is tempting to equate this phase with the appearance of public-key cryptography, but that is too narrow a view.
• It could be said that cryptography, or the art of secret writing, was born with writing itself.
• The world we know today would be impossible without cryptography.
• For this reason, public-key cryptography is also known as asymmetric cryptography.
• None of these marvels would be possible without cryptography.
• As of Android 9 (API level 28), the Crypto Java Cryptography Architecture (JCA) provider has been removed.
• Public key encryption is a technological revolution offering every citizen the opportunity to use robust cryptography.
• Cryptography techniques Cryptography is closely related to the disciplines of cryptology and cryptanalysis.
• However, cryptography makes it harder for attackers to access messages and data protected by encryption algorithms.
• Cryptography is the science of keeping information secure by transforming it into form that unintended recipients cannot understand.
• Encryption is an important part of cryptography, but doesn't encompass the entire science.
• For most of history, cryptography consisted of various substitution ciphers deployed to keep government and military communications secure.
• In fact, the development of computers and advances in cryptography went hand in hand.
• Cryptography is associated with the process of converting ordinary plain text into unintelligible text and vice-versa.
• Symmetric-key Cryptography: Both the sender and receiver share a single key.
• In Public-Key Cryptography two related keys (public and private key) are used.
• With symmetric cryptography, the same key is used for both encryption and decryption.
• Prior to the early 20th century, cryptography was mainly concerned with linguistic and lexicographic patterns.
• Computer use has thus supplanted linguistic cryptography, both for cipher design and cryptanalysis.
• Extensive open academic research into cryptography is relatively recent; it began only in the mid-1970s.
• Since then, cryptography has become a widely used tool in communications, computer networks, and computer security generally.
• But it is important to note that while cryptography is necessary for secure communications, it is not by itself sufficient.
• The second is to provide some real examples of cryptography in use today.
• It is no surprise, then, that new forms of cryptography came soon after the widespread development of computer communications.
• In cryptography, we start with the unencrypted data, referred to as plaintext.
• Cryptography deals with the actual securing of digital data.
• The primary objective of using cryptography is to provide the following four fundamental information security services.
• Cryptography may also refer to the art of cryptanalysis, by which cryptographic codes are broken.
• Collectively, the science of secure and secret communications, involving both cryptography and cryptanalysis, is known as cryptology.
• The principles of cryptography are today applied to the encryption of fax, television, and computer network communications.
• This Edureka video about what is Cryptography and why it is essential to protect the information shared across the internet.
• That’s where Encryption or Cryptography comes in.
• Further drilling down, Classical Cryptography is divided into Transposition Cipher and Substitution Cipher.
• cryptography is a package which provides cryptographic recipes and primitives to Python developers.
• In this segment, we'll discuss the fundamental concepts behind modern cryptography.
• Asymmetric keys and symmetric keys are two basic types of algorithms that are used in modern cryptography.
• In addition, cryptography also covers the obfuscation of information in images using techniques such as microdots or merging.
• When transmitting electronic data, the most common use of cryptography is to encrypt and decrypt email and other plain-text messages.
• In public key cryptography, we use a public and a private key.
• In general, cryptography provides us with a mechanism to protect data at rest, in motion, and, to a certain extent, in use.
• Provides a Cryptography Next Generation (CNG) implementation of the Triple Data Encryption Standard (3DES) algorithm.

웹 브라우저

말뭉치

1. If you’re reading this, then I hope that sometime somebody or some web site told you that doing cryptography in a web browser is a bad idea.
2. Why not put cryptography in the browser?
3. What we see happening here is cryptography being used to protect the web site’s interests, not the user’s.
4. For example, there are cryptography libraries that exist in both Java and Flash.
5. There are two main criticisms of doing cryptography in JavaScript: security and speed.
6. For example, the post makes the point that Math.random() is not a good source of randomness, and thus it is impossible to get a suitable amount of random numbers for cryptography.
7. Until recently, JavaScript has been too slow to perform the many complex computations required for secure cryptography.
8. The Console uses browser cryptography both during authentication and to protect stored values the server is not meant to see.
9. It does mean you’re following best practices and making solid steps towards a stable, secure website and can more safely use tools like browser cryptography on modern browsers.
10. Such an infrastructure would not only be useful for integrity checking cryptography code, but could be used to mitigate XSS attacks.
11. The Web Cryptography API is a proposed addition to the HTML5 specification that will support cryptography for web applications.
12. The W3C proposal for the Web Cryptography API goes by the name of Encrypted Media Extensions (EME) and is currently in the draft phase.
13. Implementation of the Web Cryptography API in the Chrome browser, and in Mozilla Firefox has already begun.
14. Although PolyCrypt implements an older design of the Web Cryptography API, it is well suited for demonstration purposes.
15. The goal of this series of blog articles is to evaluate the Web Cryptography specification before analysing the Web Cryptography API.
16. To address these problems, the Web Cryptography Working Group of the World Wide Web Consortium convened to perform client-side cryptographic operations in the native implementation of the user agent.
17. Until fairly recently, browsers did not have any built-in cryptography APIs, leading to a large number of JavaScript libraries that implemented cryptography for web applications.
18. These features, whether provided through the Web Cryptography API or through the Node.js crypto module, are often referred to as “cryptographic primitives”.
19. The Web Cryptography API uses instances of the ArrayBuffer class to represent byte sequences, but most functions also accept any TypedArray as their input.
20. Unlike many other cryptographic libraries, the Web Crypto API enforces some usage patterns of keys that correlate to known best practices in cryptography.
21. This example is provided to illustrate how to use the W3C Web Cryptography API to perform symmetric encryption inside a web browser.
22. Using this example requires a web browser that implements a compatible version of the Web Cryptography API.
23. However, through 20+ years of history of web browsers, we're at the stage where in-browser cryptography is still problematic, and best you can rely on is SSL.
24. In the next weeks, we'll summarize our experience of developing cryptography for Google Chrome, porting LibreSSL, building Themis for PNaCl, etc.
25. Server-Gated Cryptography (SGC), also known as International Step-Up by Netscape, is a defunct mechanism that was used to step up from 40-bit or 56-bit to 128-bit cipher suites with SSL.
26. Although the weaker exported browsers would only include weaker ciphers in its initial SSL handshake, the browser also contained stronger cryptography algorithms.
27. Cryptography, the art and science of secret codes, has evolved dramatically over the centuries, especially since World War II.
28. Public-key cryptography provides a safe and easy way for the SSL software to share a secret key between your browser and a Web site you visit.
29. The latest effort underway is to implement support for the Web Cryptography API.
30. API is a collection of W3C standardised cryptography primitives defined in the Web Cryptography API specification.
31. The Web Cryptography API implementation has landed as an experimental feature in Node.js 15.0.0.
32. A better implementation would be to derive users' crypto keys from their passwords using a key derivation algorithm like PBKDF2 (available via the Web Cryptography API) with a high work factor.
33. Cryptography is the cornerstone of information security, including various aspects such as data confidentiality, data integrity, authentication, and non-repudiation.
34. The WebCrypto API was created to bring these important high-level cryptography capabilities to the web.
35. This blog post first talks about the advantages of implementing web cryptography through native APIs, and then introduces an overview of the WebCrypto API itself.
36. Long before the WebCrypto API was standardized, several JavaScript cryptography libraries were created and have successfully served the open web since.
37. Asymmetric encryption (or public-key cryptography) uses a separate key for encryption and decryption.
38. Elliptic curve cryptography (ECC) relies on the algebraic structure of elliptic curves over finite fields.
39. Let's take a little aside to talk about a neat property of elliptic curve cryptography.