[Back] Enter a message, and generate a code:
In Chapter 1 the concept of defence-in-depth was discussed, where a defence system has many layers of defence. Unfortunately, as in military systems, it is not always possible to protect using front-line defences, even if there are multiple layers of them, against breaches in security (Figure 2.2). This can be because an intruder has found a weakness within the security barriers, or because the intruder has actually managed to physically locate themselves within the trusted areas. Thus all the gateway firewalls and DMZ’s cannot protect against an intruder once they have managed to base themselves physically or locally within a network. Along with this, most security systems can only guard against known types of attacks, such as in detecting known viruses. A particular problem is when new types of attacks occur, as these are more difficult to defend against. Thus a key factor is identifying threats, and how to mitigate against them. Many organisations are now rehearsing plans on how they cope with these threats, and have contingency plans. Unfortunately many other organisations have no plans for given threats, and these are the ones which are in most danger of a damaging attack. As in military systems, an allied force would setup spies whose task it is to detect intrusions, and any covert activities. Figure 2.3 illustrates this concept, where intrusion detection agents are used to listen to network traffic, and network/user activity to try and detect any breaches in security.
AZ CHFVNXP 1 NHX CEZCXVN ET OXTXZCX-AZ-OXVNH IFG OAGCSGGXO, IHXPX F OXTXZCX GJGNXM HFG MFZJ UFJXPG ET OXTXZCX. SZTEPNSZFNXUJ, FG AZ MAUANFPJ GJGNXMG, AN AG ZEN FUIFJG VEGGADUX NE VPENXCN SGAZY TPEZN-UAZX OXTXZCXG, XBXZ AT NHXPX FPX MSUNAVUX UFJXPG ET NHXM, FYFAZGN DPXFCHXG AZ GXCSPANJ (TAYSPX 2.2). NHAG CFZ DX DXCFSGX FZ AZNPSOXP HFG TESZO F IXFKZXGG IANHAZ NHX GXCSPANJ DFPPAXPG, EP DXCFSGX NHX AZNPSOXP HFG FCNSFUUJ MFZFYXO NE VHJGACFUUJ UECFNX NHXMGXUBXG IANHAZ NHX NPSGNXO FPXFG. NHSG FUU NHX YFNXIFJ TAPXIFUUG FZO OML’G CFZZEN VPENXCN FYFAZGN FZ AZNPSOXP EZCX NHXJ HFBX MFZFYXO NE DFGX NHXMGXUBXG VHJGACFUUJ EP UECFUUJ IANHAZ F ZXNIEPK. FUEZY IANH NHAG, MEGN GXCSPANJ GJGNXMG CFZ EZUJ YSFPO FYFAZGN KZEIZ NJVXG ET FNNFCKG, GSCH FG AZ OXNXCNAZY KZEIZ BAPSGXG. F VFPNACSUFP VPEDUXM AG IHXZ ZXI NJVXG ET FNNFCKG ECCSP, FG NHXGX FPX MEPX OATTACSUN NE OXTXZO FYFAZGN. NHSG F KXJ TFCNEP AG AOXZNATJAZY NHPXFNG, FZO HEI NE MANAYFNX FYFAZGN NHXM. MFZJ EPYFZAGFNAEZG FPX ZEI PXHXFPGAZY VUFZG EZ HEI NHXJ CEVX IANH NHXGX NHPXFNG, FZO HFBX CEZNAZYXZCJ VUFZG. SZTEPNSZFNXUJ MFZJ ENHXP EPYFZAGFNAEZG HFBX ZE VUFZG TEP YABXZ NHPXFNG, FZO NHXGX FPX NHX EZXG IHACH FPX AZ MEGN OFZYXP ET F OFMFYAZY FNNFCK. FG AZ MAUANFPJ GJGNXMG, FZ FUUAXO TEPCX IESUO GXNSV GVAXG IHEGX NFGK AN AG NE OXNXCN AZNPSGAEZG, FZO FZJ CEBXPN FCNABANAXG. TAYSPX 2.3 AUUSGNPFNXG NHAG CEZCXVN, IHXPX AZNPSGAEZ OXNXCNAEZ FYXZNG FPX SGXO NE UAGNXZ NE ZXNIEPK NPFTTAC, FZO ZXNIEPK/SGXP FCNABANJ NE NPJ FZO OXNXCN FZJ DPXFCHXG AZ GXCSPANJ.
This table shows the occurances of the letters in the text (ignoring the case of the letters):
This table shows how the text matches a normal probability to text (where 'E' has the highest level of occurance and 'Z' has the least). The grey rows show what would be expected for the order, and the red one shows what your text gives for the order: