Jim’s company regularly performs backups of their critical servers. But the company cannot afford to send backup tapes to an off-site vendor for long-term storage and archiving. Instead, Jim’s company keeps the backup tapes in a safe in the office. Jim’s company is audited each year, and the results from this year’s audit show a risk because backup tapes are not stored off-site. The Manager of Information Technology has a plan to take the backup tapes home with him and wants to know what two things he can do to secure the backup tapes while in transit?
Correct Answer:
A
what firewall evasion scanning technique make use of a zombie system that has low network activity as well as its fragment identification numbers?
Correct Answer:
D
The idle scan could be a communications protocol port scan technique that consists of causing spoofed packets to a pc to seek out out what services square measure obtainable. this can be accomplished by impersonating another pc whose network traffic is extremely slow or nonexistent (that is, not transmission or receiving information). this might be associate idle pc, known as a “zombie”.
This action are often done through common code network utilities like nmap and hping. The attack involves causing solid packets to a particular machine target in an attempt to seek out distinct characteristics of another zombie machine. The attack is refined as a result of there’s no interaction between the offender pc and also the target: the offender interacts solely with the “zombie” pc.
This exploit functions with 2 functions, as a port scanner and a clerk of sure informatics relationships between machines. The target system interacts with the “zombie” pc and distinction in behavior are often discovered mistreatment totally different|completely different “zombies” with proof of various privileges granted by the target to different computers.
The overall intention behind the idle scan is to “check the port standing whereas remaining utterly invisible to the targeted host.”
The first step in execution associate idle scan is to seek out associate applicable zombie. It must assign informatics ID packets incrementally on a worldwide (rather than per-host it communicates with) basis. It ought to be idle (hence the scan name), as extraneous traffic can raise its informatics ID sequence, confusing the scan logic. The lower the latency between the offender and also the zombie, and between the zombie and also the target, the quicker the scan can proceed.
Note that once a port is open, IPIDs increment by a pair of. Following is that the sequence:
offender to focus on -> SYN, target to zombie ->SYN/ACK, Zombie to focus on -> RST (IPID increment by 1) currently offender tries to probe zombie for result. offender to Zombie ->SYN/ACK, Zombie to offender
-> RST (IPID increment by 1)
So, during this method IPID increments by a pair of finally.
When associate idle scan is tried, tools (for example nmap) tests the projected zombie and reports any issues with it. If one does not work, attempt another. Enough net hosts square measure vulnerable that zombie candidates are not exhausting to seek out. a standard approach is to easily execute a ping sweep of some network. selecting a network close to your supply address, or close to the target, produces higher results. you’ll be able to attempt associate idle scan mistreatment every obtainable host from the ping sweep results till you discover one that works. As usual, it’s best to raise permission before mistreatment someone’s machines for surprising functions like idle scanning.
Simple network devices typically create nice zombies as a result of {they square measure|they’re} normally each underused (idle) and designed with straightforward network stacks that are susceptible to informatics ID traffic detection.
While distinguishing an acceptable zombie takes some initial work, you’ll be able to keep re-using the nice ones. as an alternative, there are some analysis on utilizing unplanned public internet services as zombie hosts to perform similar idle scans. leverage the approach a number of these services perform departing connections upon user submissions will function some quite poor’s man idle scanning.
While examining audit logs, you discover that people are able to telnet into the SMTP server on port 25. You would like to block this, though you do not see any evidence of an attack or other wrong doing. However, you are concerned about affecting the normal functionality of the email server. From the following options choose how best you can achieve this objective?
Correct Answer:
E
in this form of encryption algorithm, every Individual block contains 64-bit data, and three keys are used, where each key consists of 56 bits. Which is this encryption algorithm?
Correct Answer:
B
Triple DES is another mode of DES operation. It takes three 64-bit keys, for an overall key length of 192 bits. In Stealth, you merely type within the entire 192-bit (24 character) key instead of entering each of the three keys individually. The Triple DES DLL then breaks the user-provided key into three subkeys, padding the keys if necessary in order that they are each 64 bits long. The procedure for encryption is strictly an equivalent as regular DES, but it’s repeated 3 times , hence the name Triple DES. the info is encrypted with the primary key, decrypted with the second key, and eventually encrypted again with the third key.Triple DES runs 3 times slower than DES, but is far safer if used properly. The procedure for decrypting something is that the same because the procedure for encryption, except it’s executed in reverse. Like DES, data is encrypted and decrypted in 64-bit chunks. Although the input key for DES is 64 bits long, the particular key employed by DES is merely 56 bits long . the smallest amount significant (right-most) bit in each byte may be a parity , and will be set in order that there are always an odd number of 1s in every byte. These parity bits are ignored, so only the seven most vital bits of every byte are used, leading to a key length of 56 bits. this suggests that the effective key strength for Triple DES is really 168 bits because each of the three keys contains 8 parity bits that aren’t used during the encryption process.Triple DES ModesTriple ECB (Electronic Code Book)• This variant of Triple DES works precisely the same way because the ECB mode of DES.• this is often the foremost commonly used mode of operation.Triple CBC (Cipher Block Chaining)• This method is extremely almost like the quality DES CBC mode.• like Triple ECB, the effective key length is 168 bits and keys are utilized in an equivalent manner, as described above, but the chaining features of CBC mode also are employed.• the primary 64-bit key acts because the Initialization Vector to DES.• Triple ECB is then executed for one 64-bit block of plaintext.• The resulting ciphertext is then XORed with subsequent plaintext block to be encrypted, and therefore the procedure is repeated.• This method adds an additional layer of security to Triple DES and is therefore safer than Triple ECB, although it’s not used as widely as Triple ECB.
Which service in a PKI will vouch for the identity of an individual or company?
Correct Answer:
D