Network Design The WritePass Journal

Network Design Introduction Network Design IntroductionTransport Layer SecurityHow it worksTLS Handshake ProtocolTLS Record ProtocolWhere TLS is usedHow Secure Is It?Secure ShellHow it worksBibliographyRelated Introduction I have been asked to research and compare two of the most widely used internet security protocols, Transport Layer Security (TLS) and Secure Shell (SSH). In this report I shall research both protocols and then compare the two listing similarities and differences in how they operate as security protocols. I shall examine the features of both giving advantages and disadvantages, examples will be given for both security protocols and any infrastructure needs. As per instruction I will be using varied sources for my research including books, magazines and the internet, as with any report I shall reference all of my sources of information. Transport Layer Security Today the need for network security is of uppermost importance. We would all like to think that data is transmitted securely, but what if it wasn’t. Credit card crime for example would be a lot easier if there was no network security. This is one of many reasons why we need network security, and to achieve this we need protocols to secure the end to end transmission of data. An earlier protocol that was widely used in the early 1990’s this was the Secure Socket Layer protocol (SSL). SSL was developed by Netscape but had some security flaws and used a weak algorithm and did not encrypt all of the information. Three versions of SSL where developed by Netscape and after the third the Internet Engineering Task Force (IETF) were called in to develop an Internet standard protocol. This protocol was called the Transport Layer Security (TLS) protocol.   The main goal was to supply a means to allow secure connections for networks including the internet.    How it works The Transport Layer Security protocol uses complex algorithms to encrypt information as it is sent over the network. The protocol comprises of two main layers the Transport Layer Security Record and the Handshake Protocol. TLS Handshake Protocol The TLS Handshake protocol is used to; in principle agree a secret between the two applications before any data is sent. This protocol works above the TLS Record protocol and sends the secrets in the order in which they have to be sent. The most important feature here is that no data is sent in securing connection, the first bit sent is a start bit to the whole process and only when secure connection achieved is data sent over the network. TLS Record Protocol The Transport Layer Security Record encrypts the data using cryptography and uses a unique key for connection which is received from the Handshake protocol. The TLS Record protocol may be used with or without encryption. The data which has been encrypted is then sent down to the Transmission Control (TCP) layer for transport. The record also adds a Message Authentication Code (MAC) to the outward data and confirms using the MAC. I have used the image below to show how this is achieved. Where TLS is used The Transport Layer Security protocol is normally used, above any of the Transport Layer protocols. So the TLS protocol operates at Open Systems Interconnection (OSI) level 4, where it joins itself to other transport layer protocols, for example Hypertext Protocol( HTTP) and File Transfer Protocol (FTP) although its main partner is Transmission Control Protocol( TCP). Main area of use would be the internet in applications that need end to end security. This data is usually carried by HTTP and with TLS becomes HTTPS. TLS is therefore used to secure connections with e-commerce sites. VoIP also uses TLS to secure its data transmissions.† TLS and SSL are most widely recognized as the protocols that provide secure HTTP (HTTPS) for Internet transactions between Web browsers and Web servers.† (Microsoft, 2011) The Transport Layer Security protocol is also used in setting up Virtual Private Networks (VPN), where end to end security is a must but again is used alongside other protocols. How Secure Is It? Secure Shell The Secure Shell (SSH) is used for safe remote access between clients through an untrusted network. SSH is widely used software in network security. The need for such protocols is paramount in today’s technology based world. In the modern office for example employees may wish to transfer files to their home computer for completion, this would be an unwise option if it wasn’t for security protocols. A man in the middle attack could take place by listening on the network for traffic and picking up all your company secrets or personal ones. How it works The Secure Shell develops a channel for executing a shell on a remote machine. The channel has encryption at both ends of the connection. The most important aspects of SSH is that it authenticates the connection and encrypts the data it also ensures that the data sent is the data received. Bibliography TLS protocol. (2011, 03 23). Retrieved March 23, 2011, from wikipedia: http://it.wikipedia.org/wiki/File:EAP-TLS_handshake.png Microsoft. (2011, March 23). What is TLS. Retrieved March 23, 2011, from Microsoft TechNet: http://technet.microsoft.com/en-us/library/cc784450%28WS.10%29.aspx

French Accent Homographs

French Accent Homographs You may not realize it, but French accents have a purpose. While some accents just signify that an S used to follow that vowel in Old French (e.g., à ©tudiant used to be spelled estudiant), most French accents indicate the correct pronunciation of the letter they modify. In addition, there are dozens of French word pairs which are spelled (though not always pronounced) the same other than accents. To avoid confusion, you should always distinguish between these words by using the correct accents. Note: It is grammatically acceptable to leave accents off capital letters. However, since missing accents may cause confusion in pronunciation and meaning and are technically spelling mistakes, I feel that one should always write with accents. a - third person singular of avoir (to have) - (preposition) to, at, inacre - acreà ¢cre - (adjective) acrid, pungentà ¢ge - ageà ¢gà © - (adjective) oldaie - first person singular subjunctive and second person singular imperative of avoiraà ¯e - (interjection) oucharrià ©rà © - (adjective) overdue, backward; (noun) backlog, arrearsarrià ¨re - back, stern, rear, aftbronze - bronze objectbronzà © - past participle of bronzer (to tan, bronze)à §a - (indefinite demonstrative pronoun) that, ità § et l - here and therecolle - gluecollà © - past participle of coller (to glue)congres - eelscongrà ¨s - conference, congresscote - quotation, quoted value, ratingcotà © - highly thought of / rated (past participle of cà ´ter)cà ´te - rib, slope, coastlinecà ´tà © - sidecrà ªpe - crepe (thin pancake), crepe papercrà ªpà © - past participle of crà ªper (to backcomb, crimp)cure - cure, treatmentcurà © - priest; past participle of curer (to clean out)de - (preposition) of, fr omdà © - thimble, diedes - (indefinite article, partitive article) some; contraction of de lesdà ¨s - (preposition) fromdiffà ©rent - differentdiffà ¨rent - third person plural conjugation of diffà ©rer (to differ)du - contraction of de ledà » - past participle of devoir (to have to)-e vs à ©At the end of -er verbs, the accent is the difference between the first and third person singular present tense and the past participle-e - à ©tudie, parle, visite-à © - à ©tudià ©, parlà ©, visità ©entre - (preposition) betweenentrà © - past participle of entrer (to enter)es - second person singular of à ªtre (to be)à ¨s - contraction of en lesà ªtes - second person plural of à ªtreà ©tà ©s - summerseut - third person singular passà © simple of avoireà »t - third person singular imperfect subjunctive of avoirferme - farmfermà © - past participle of fermer (to close)fut - third person singular passà © simple of à ªtrefà »t - third person singular imperfect subjuncti ve of à ªtre gà ¨ne - genegà ªne - trouble, bother, embarrassmentgà ªnà © - (adjective) short of, embarrassed; past participle of gà ªner (to bother) grade - rank, degreegradà © - officerhaler - to haul inhà ¢ler - to tanillustre - illustrious, renownedillustrà © - illustratedinfecte - (fem adjective) revolting, filthy, obnoxiousinfectà © - infected, contaminatedinterne (adj) internal, inner; (noun) boarder, interninternà © - inmate (of a mental hospital), internee (politics)jeune - (adjective) youngjeà »ne - fastingjuge - judgejugà © - past participle of juger (to judge)la - (definite article) the; (direct object pronoun) her, itl - (adverb) therelevà © - survey; past participle of lever (to lift, raise)là ¨ve - first and third person singular of lever (applies to many stem-changing verbs)liquide - liquidliquidà © - past participle of liquider (to settle, pay; to liquidate, sell off; [inf] to finish off)mais - (conjunction) butmaà ¯s - cornmarche - walking, step, stairmarchà © - market; past participle of marcher (to walk, march; to work)masse - massmassà © - past participle of masser (to assemble, mass, group)mat - checkmate; (adjective) matte, dullmà ¢t - mast, polemater - to subdue; (familiar) to ogle; to caulk; (familiar noun) mom, mummà ¢ter - to mastmà ©mà © - (baby talk) grannymà ªme - (adverb) samemeuble - piece of furnituremeublà © - (adjective) furnishedmodelà © - contours, relief; past participle of modeler (to model, shape, style, mold)modà ¨le - model, designmur - wallmà »r - (adjective) ripenotre - (possessive adjective) ournà ´tre - (possessive pronoun) oursnuance - shade, hue, slight difference, nuancenuancà © - (adjective) qualified, balanced, nuanced; past participle of nuancer (to shade, qualify, nuance)ou - (conjunction) oroà ¹ - (adverb) wherepà ¢te - pastry, paste; pà ¢tes - pastpà ¢tà © - pà ¢tà ©pà ©chà © - past participle of pà ©cherpà ªche - peach, fishingpà ©cher - to sinpà ªcher - to fishpà ©cheur - sinnerpà ªcheur - fishermanprà ªte - (feminine adjective) readyprà ªtà © - past participle of prà ªter (to lend)rate - spleenratà © - past participle of rater (to fail, miss)relà ¢che - rest, respiterelà ¢chà © - loose, laxreste - rest, leftoverrestà © - past participle of rester (to stay)retraite - retreat, retirementretraità © - retired person; past participle of retraiter (to reprocess)rot - belch, burprà ´t - (archaic) roastroue - wheelrouà © - (adj) cunning, sly; un rouà © - cunning/sly person; past participle of rouer (to beat/thrash)roule - first and third person singular of rouler (to wheel/roll along)roulà © - curved, rolledsale - dirtysalà © - saltysinistre (adj) gloomy, sinister; (m noun) accident, disaster, damagesinistrà © (adj) stricken, devastated; (m noun) disaster victimsublime - sublimesublimà © - sublimatedsuicide - act of suicidesuicidà © - victim of suicidesur - (preposition) onsà »r - (adjective) suretache - mark, spot, staintà ¢che - taskvalide - able-bodied, fit, validvalidà © - validatedvide - emptyvidà © - worn out; past participle of vider (to empty; to wear out)votre - (poss essive adjective) yourvà ´tre - (possessive pronoun) yours