[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.
CJ WAHSVOF 1 VAO WTJWOSV TK ROKOJWO-CJ-ROSVA UHM RCMWPMMOR, UAOFO H ROKOJWO MXMVOE AHM EHJX DHXOFM TK ROKOJWO. PJKTFVPJHVODX, HM CJ ECDCVHFX MXMVOEM, CV CM JTV HDUHXM STMMCLDO VT SFTVOWV PMCJQ KFTJV-DCJO ROKOJWOM, OYOJ CK VAOFO HFO EPDVCSDO DHXOFM TK VAOE, HQHCJMV LFOHWAOM CJ MOWPFCVX (KCQPFO 2.2). VACM WHJ LO LOWHPMO HJ CJVFPROF AHM KTPJR H UOHBJOMM UCVACJ VAO MOWPFCVX LHFFCOFM, TF LOWHPMO VAO CJVFPROF AHM HWVPHDDX EHJHQOR VT SAXMCWHDDX DTWHVO VAOEMODYOM UCVACJ VAO VFPMVOR HFOHM. VAPM HDD VAO QHVOUHX KCFOUHDDM HJR REI’M WHJJTV SFTVOWV HQHCJMV HJ CJVFPROF TJWO VAOX AHYO EHJHQOR VT LHMO VAOEMODYOM SAXMCWHDDX TF DTWHDDX UCVACJ H JOVUTFB. HDTJQ UCVA VACM, ETMV MOWPFCVX MXMVOEM WHJ TJDX QPHFR HQHCJMV BJTUJ VXSOM TK HVVHWBM, MPWA HM CJ ROVOWVCJQ BJTUJ YCFPMOM. H SHFVCWPDHF SFTLDOE CM UAOJ JOU VXSOM TK HVVHWBM TWWPF, HM VAOMO HFO ETFO RCKKCWPDV VT ROKOJR HQHCJMV. VAPM H BOX KHWVTF CM CROJVCKXCJQ VAFOHVM, HJR ATU VT ECVCQHVO HQHCJMV VAOE. EHJX TFQHJCMHVCTJM HFO JTU FOAOHFMCJQ SDHJM TJ ATU VAOX WTSO UCVA VAOMO VAFOHVM, HJR AHYO WTJVCJQOJWX SDHJM. PJKTFVPJHVODX EHJX TVAOF TFQHJCMHVCTJM AHYO JT SDHJM KTF QCYOJ VAFOHVM, HJR VAOMO HFO VAO TJOM UACWA HFO CJ ETMV RHJQOF TK H RHEHQCJQ HVVHWB. HM CJ ECDCVHFX MXMVOEM, HJ HDDCOR KTFWO UTPDR MOVPS MSCOM UATMO VHMB CV CM VT ROVOWV CJVFPMCTJM, HJR HJX WTYOFV HWVCYCVCOM. KCQPFO 2.3 CDDPMVFHVOM VACM WTJWOSV, UAOFO CJVFPMCTJ ROVOWVCTJ HQOJVM HFO PMOR VT DCMVOJ VT JOVUTFB VFHKKCW, HJR JOVUTFB/PMOF HWVCYCVX VT VFX HJR ROVOWV HJX LFOHWAOM CJ MOWPFCVX.
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: