They change to keep authentication and integrity.
2. Why are the MD5sum and SHA1sum hash values the same every time you calculate for the “example.txt” sample fi le? What if they were different when you re-calculated the hash value at the other end?
These are the same to verify authentication and integrity. If they don’t match the data has been compromised.
3. If you were using corporate e-mail for internal and external communications but did not want to encrypt an e-mail message, what other security countermeasure can you deploy to ensure message integrity?
They could use digital signatures in the email.
4. If you are using corporate e-mail for external communications that contain confidential information, what other security countermeasure can you deploy to maximize confidentiality of e-mail transmissions through the Internet?
They can use digital signatures along with cryptography.
5. What is the difference between MD5sum and SHA1sum hashing calculations? Which is better and why?
MD5sum is a one-way has function that has a 128 bit has for the input. SHA1sum processes up to 512 and adds padding. Sha1sum is better because padding is added to ensure the right numbers.
6. Where can you store your public keys or public certificate fi les in the public domain? Is this the same thing as a public key infrastructure (PKI) server?
7. What do you need if you want to decrypt encrypted messages and fi les from a trusted sender?
You would need the public key to decrypt the message.
8. What encryption mechanisms are built into Microsoft® Windows XP Professional?
EFS is what is built into Microsoft Windows XP.
9. Which Windows encryption mechanism provides full disk encryption and uses the Trusted Platform Module to do so? Do you recommend that end-users encrypt their personal hard drives on Microsoft® Windows platforms and workstations?
Bitlocker can be used for a full disk encryption. It would depend on their system and need for encryption.
10. What happens if you have a forensic copy of a hard drive that happens to have the entire disk encrypted that you try to view with standard forensic tools? 2
It would not be able to be decrypted unless the keys were available.
