abcdefghijklmnopqrstuvwxyz
TZLQROIKDHGMPSEVYXAWFCNJBU
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.
DS LKTVWRX 1 WKR LESLRVW EO QRORSLR-DS-QRVWK NTA QDALFAARQ, NKRXR T QRORSLR ABAWRP KTA PTSB MTBRXA EO QRORSLR. FSOEXWFSTWRMB, TA DS PDMDWTXB ABAWRPA, DW DA SEW TMNTBA VEAADZMR WE VXEWRLW FADSI OXESW-MDSR QRORSLRA, RCRS DO WKRXR TXR PFMWDVMR MTBRXA EO WKRP, TITDSAW ZXRTLKRA DS ARLFXDWB (ODIFXR 2.2). WKDA LTS ZR ZRLTFAR TS DSWXFQRX KTA OEFSQ T NRTGSRAA NDWKDS WKR ARLFXDWB ZTXXDRXA, EX ZRLTFAR WKR DSWXFQRX KTA TLWFTMMB PTSTIRQ WE VKBADLTMMB MELTWR WKRPARMCRA NDWKDS WKR WXFAWRQ TXRTA. WKFA TMM WKR ITWRNTB ODXRNTMMA TSQ QPU’A LTSSEW VXEWRLW TITDSAW TS DSWXFQRX ESLR WKRB KTCR PTSTIRQ WE ZTAR WKRPARMCRA VKBADLTMMB EX MELTMMB NDWKDS T SRWNEXG. TMESI NDWK WKDA, PEAW ARLFXDWB ABAWRPA LTS ESMB IFTXQ TITDSAW GSENS WBVRA EO TWWTLGA, AFLK TA DS QRWRLWDSI GSENS CDXFARA. T VTXWDLFMTX VXEZMRP DA NKRS SRN WBVRA EO TWWTLGA ELLFX, TA WKRAR TXR PEXR QDOODLFMW WE QRORSQ TITDSAW. WKFA T GRB OTLWEX DA DQRSWDOBDSI WKXRTWA, TSQ KEN WE PDWDITWR TITDSAW WKRP. PTSB EXITSDATWDESA TXR SEN XRKRTXADSI VMTSA ES KEN WKRB LEVR NDWK WKRAR WKXRTWA, TSQ KTCR LESWDSIRSLB VMTSA. FSOEXWFSTWRMB PTSB EWKRX EXITSDATWDESA KTCR SE VMTSA OEX IDCRS WKXRTWA, TSQ WKRAR TXR WKR ESRA NKDLK TXR DS PEAW QTSIRX EO T QTPTIDSI TWWTLG. TA DS PDMDWTXB ABAWRPA, TS TMMDRQ OEXLR NEFMQ ARWFV AVDRA NKEAR WTAG DW DA WE QRWRLW DSWXFADESA, TSQ TSB LECRXW TLWDCDWDRA. ODIFXR 2.3 DMMFAWXTWRA WKDA LESLRVW, NKRXR DSWXFADES QRWRLWDES TIRSWA TXR FARQ WE MDAWRS WE SRWNEXG WXTOODL, TSQ SRWNEXG/FARX TLWDCDWB WE WXB TSQ QRWRLW TSB ZXRTLKRA DS ARLFXDWB.
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: