One Article Review

Accueil - L'article:
Source Veracode.webp Veracode
Identifiant 2388411
Date de publication 2021-02-23 09:45:03 (vue: 2021-02-23 15:05:25)
Titre Message Authentication Code (MAC) Using Java
Texte This is the seventh entry in this blog series on using Java Cryptography securely. Starting from theツ?basics we began diving deeper into various basic cryptographic primitives such as Cryptographically Secure Random Number Generator, symmetric & asymmetric encryption/decryption & hashes. After taking a brief interval, we caught-up with cryptographic updates in the latest Java version. Skip to the TL; DR At this point, we are well equipped to discuss some of the most commonly encountered cryptographic schemes. Let???s start by looking at applications designed around symmetric cryptography, starting with Message Authentication Code in this post. Thankfully, Java provides us with rich, easy-to-use APIs for lot of these applications, relieving us to build up crypto systems from primitives. Overview: What is MAC? Encryption provides us with the confidentiality service of cryptography. In a lot of applications (think of any kind of secure communication), receiving parties need to be assured of the origin of the message (authenticity) and make sure the message is received untampered (integrity). Hashing does provide us with integrity services but not authenticity. In order to get both, we would need a separate crypto-scheme that would compute authentication tags (a.k.a Message Authentication Codes or MACs). Message Authentication Code (MAC) crypto scheme, unlike hashing, involves a secret key to restrict integrity capabilities to only parties that have access to it, which is whyツ?it is also called keyed hashing or the more relevant term: cryptographic hash/checksum. MAC can be constructed using ciphers (such as CMAC & GMAC) or hashes (HMAC). However, it is a bit tricky to get cipher-based MACs right. JDK doesn???t provide any cipher-based MAC constructions too. Rule of thumb: stay away from cipher-based MAC, even if encountered in some 3rd party providers. We already have a more trouble-free option with HMAC, so why risk it? Going ahead, we will just be focusing on HMACs. HowTo: How Does it Work? This crypto scheme works around a central MAC algorithm, which takes 2 pieces of information; symmetric key (k) and plain text message to be authenticated (M) and computes Message Authentication Code. Thus, MAC = HMAC(K,M). The MAC algorithm (HMAC) takes the message (M) of arbitrary length and generates fixed size authentication tags (or MACs). Message Authentication Steps: A symmetric key(K) is established between sender and receiver, typically using a secure channel. The sender computes MAC, using a secure HMAC algorithm on message M and symmetric key(K). The message is appended with MAC and sent across to the receiver i.e., M || MAC is sent to the receiver. Receiver pulls apart M and MAC and recomputes MAC from M using the same HMAC algorithm as sender and symmetric key(K). If the receiver computed MAC == sender sent MAC, authenticity, and integrity of received M is verified. This implies messages have reached received untampered from the stated sender. HowTo: Construction of HMAC
Envoyé Oui
Condensat 107 128 128ツ 198 224 256 384 3rd 512 6151: 7518 7519 800 90s about access accessed across add additions after ahead algorithm algorithms all already also any apart api apis appended applications arbitrary architecture are are: around assured asymmetric attached aumasson authenticated authentication authenticity authorization away backend backward based basic basics began being between bit bits blog blogs/conferences/books book both brief build but called can capabilities caught central channel checked christof cipher ciphers class clear cleared client cmac code code: codes collision commonly communication compatibility complete compute computed computemac computes computing concludes confidentiality considerations constructed construction constructions continue corresponding crucial crypto cryptographic cryptographically cryptography data decisions: deeper design designed developers digest discouraged discuss discussed discusses discussion discussions diving documentation: does doesn dofinal don door due each easy else encoded encounter encountered encryption encryption/decryption endpoints entry equals equipped establish established etc even example exclusive expected experiment explicitly families family fips fits; fixed focusing free from future generate generated generatekey generates generator get getbytes getencoded getinstance given gmac going hash hash/checksum hashes hashing have having hmac hmackey hmacmd5 hmacs hmacsha1 hmacsha224 hmacsha256 hmacsha3 hmacsha384 hmacsha512 hmacsha512/224 hmacsha512/256 holds how however howto: identical ids impact implement implements implies includes information; init initialize initializing integrity interval introduction: invoking involved involves its jan java jca jdk jean json just jwt key keyed keygen keygenerator keying keys kind latest length let list look looking lot lower mac maccomputationapi macs mainly make material md5 mechanisms mentions message messages microservice minimum modern more most names need new nist not note: note:ツ notes number obj object one only option oracle/java order origin other out output overview: paar parties party passed payload peeping pelzl philippe pieces plain point post posts primitives protocols provide provided provider providers provides providing pseudo pulls purposes putting random reached reasons received receivedmac receiver receiving recommended recomputes refer references release relevant relieving request required resistance restrict return rfc rich right risk rule safe safeguarded said same scheme schemes secret secretkey secretkeyspec section secure securely security seeing send sender sendermac sending sent separate series serious server service services session seventh severely sha sha1 sha2 sha256 sha3 shared should side sides signature signing signs size skip some specify ssh standard standards start starting stated stay step steps: strength string such summarizing sun support sure sure: symmetric systems tags takes taking talking tampered term: terms text thankfully them thereafter these theツ think those thumb: thus title tl; tls together tokens too toツ tricky trouble trust ts: tuned turn two typically underlyi underlying understanding unlike untampered upcoming update updates use used using various verified verifies verify version very weakness web well what where which why whyツ will work works would your
Tags
Stories
Notes
Move


L'article ne semble pas avoir été repris aprés sa publication.


L'article ne semble pas avoir été repris sur un précédent.
My email: