Computer Security Essay Example | Topics and Well Written Essays - 2000 words

Computer Security - Essay Example Characteristics of the attacker Motivation The motivation is to view encrypted files within the limited 9 days’ time frame after which the information loses relevance to the attacker. Access The attacker has only access to physical location of the workstation though the time is limited to only 43 minutes. Skills and risk aversion The attacker is risk averse and has idea on file encryption techniques. The attacker is not mindful of the legal and ethical ramifications of the operation but he is not willing to attain his goal through violent means. Basic Attack tree Possible attacks Special Equipment Required Attack tree against AES Goal: Read a message encrypted with AES 1. Decrypt the message itself. (OR) 1.1. Break asymmetric encryption.(OR) 1.1.1. Brute-force breaks asymmetric encryption. (OR) 1.1.2. Mathematically break asymmetric encryption (OR) 1.1.2.1. Break RSA. (OR) 1.1.2.2. Factor RSA modulus/calculate AES discrete log. 1.1.3 Cryptanalyze asymmetric encryption 1.1.3.1. General cryptanalysis of RSA/ AES (OR) 1.1.3.2. Exploiting weakness in RSA/ AES. (OR) 1.1.3.3. Timing attacks on RSA/ AES. 1.2. Break symmetric-key encryption. (OR) 1.2.1. Brute-force break symmetric-key encryption. (OR) 1.2.2. Cryptanalysis of symmetric-key encryption. 2. ... 2.1.3. Have the file encrypted with a different public key in the background unknown to the owner. 2.2. Have the owner sign the encrypted symmetric key. (OR) 2.3. Monitor owner’s computer memory. (OR) 2.4. Monitor other user back-up storage memory. (OR) 2.5. Determine the key from pseudorandom number generator. (OR) 2.5.1. Determine the state of randseed. Bin when the message was encrypted. (OR) 2.5.2. Implant software (virus) that deterministically alters the state of randseed.bin. (OR) 2.5.3. Implant the software that directly affects the choice of symmetric key. 2.6. Implant a virus that exposes the symmetric key. 3. Get owner to (help) decrypt message. (OR) 3.1. Chosen cipher text attack on symmetric key. (OR) 3.2. Chosen cipher text attack on public key. (OR) 3.3. Ghost the drives to an external storage medium. (OR) 3.4. Monitor outgoing data from the owner’s computers through the network. (OR) 3.5. Intercept transferable data through the network (OR) 3.6. Read dec rypted intercepted file. 3.6.1. Copy the message from the owner’s hard drive or virtual memory. (OR) 3.6.2. Copy the files from back-up media (OR) 3.6.3. Monitor network traffic. (OR) 3.6.4. Use electromagnetic snooping techniques to read files as they are displayed on the screen (OR) 3.6.5. Recover read message from print-out 4. Obtain private key from the owner 4.1. Factor RSA modulus/ calculate AES discrete log. (OR) 4.2. Get private key of owner. (OR) 4.2.1. Obtain encrypted owners private key ring. (OR) 4.2.1.1. Copy it from owner’s hard drive. (OR) 4.2.1.2. Copy it from disk backups. (OR) 4.2.1.3. Monitor network traffic. (OR) 4.2.1.4. Implant virus or worm to expose copy of the encrypted private key. 4.2.2. Decrypt Private Key.

What are the ethics behind photojournalism and a real life newspaper Essay

What are the ethics behind photojournalism and a real life newspaper decision to print or not to print a photograph - Essay Example â€Å"The production, presentation, and consumption of visual messages in all manner of media can be justifiably sliced in separate technological, historical, cultural and critical perspectives. The requirements for theory building at each stage are different† (Elliott & Lester, 2002). And while it is recognized that â€Å"Photography is the only ‘language’ understood in all parts of the world, and bridging all nations and cultures† (Helmut Gernsheim cited in Elliott & Lester, 2002), it is also acknowledged that â€Å"photographs supply information without having a language of their own. Photographs quote rather than translate from reality† (John Berger cited in Elliott & Lester, 2002). The difficulty arises from the variety of social, political and cultural approaches that can be taken in the interpretation of an image. Added to this is the greater ability of photographers and photojournalists to manipulate images in many different ways as a means o f achieving the image sought. In determining the ethics involved in the decisions made by photojournalists and their editors regarding whether or not to print a particular image, then, it is necessary to take into consideration the â€Å"intent of the image creator and the not-so-blank canvas of the image consumer† (Elliott & Lester, 2002) as these various approaches come into play. There have been many ethical theories proposed to serve as guidelines for the photojournalist and others regarding what types of images to display or not to display. There are six main theories that can, and should, be applied to photojournalism. These include the categorical imperative, utilitarianism, hedonism, the golden mean, the golden rule and the veil of ignorance. Categorical imperative, suggested by Immanuel Kant, refers to doing the right thing regardless of any extenuating