Commit aac0437

@@ -5,80 +5,80 @@ Assignment 4
 
 1. Why is it important to distinguish between mechanisms of protection and policies of protection?
 
-  Protection mechanisms are used to constrain the potential senders and/or
-  receivers of a message and to make sure that data is transmitted securely.
-  This includes things like cryptographic/digital signatures to ensure that a
-  piece of data or message hasn't been tampered with and/or to verify that data
-  was produced by trusted parties. This is used in many different protocols such
-  as security assertion markup language (SAML) transactions, transport layer
-  security (TLS), OAuth 2.0 and more.
+    Protection mechanisms are used to constrain the potential senders and/or
+    receivers of a message and to make sure that data is transmitted securely.
+    This includes things like cryptographic/digital signatures to ensure that a
+    piece of data or message hasn't been tampered with and/or to verify that data
+    was produced by trusted parties. This is used in many different protocols such
+    as security assertion markup language (SAML) transactions, transport layer
+    security (TLS), OAuth 2.0 and more.
 
-  Protection policies are used to enforce constraints on what things can be
-  done. Examples of this include absolute and relative session timeout policies
-  and acceptable TLS cipher suites. Policies can change over time as modern
-  cipher suites are released and vulnerabilites, and knowledge is improved.
+    Protection policies are used to enforce constraints on what things can be
+    done. Examples of this include absolute and relative session timeout policies
+    and acceptable TLS cipher suites. Policies can change over time as modern
+    cipher suites are released and vulnerabilites, and knowledge is improved.
 
 
-  Separating mechanisum from policy is more flexible because policies are likely
-  to change over time. Policy changes might require changes in the underlying
-  mechanism.
+    Separating mechanisum from policy is more flexible because policies are likely
+    to change over time. Policy changes might require changes in the underlying
+    mechanism.
 
-  Protection mechanisms determine **how** to do something and protection policies
-  determine **what** will be done.
+    Protection mechanisms determine **how** to do something and protection policies
+    determine **what** will be done.
 
 1. What is an access matrix, and how can it be implemented?
 
-  A model of protection known as the access matrix represents which domains have
-  access to which objects.
+    A model of protection known as the access matrix represents which domains have
+    access to which objects.
 
-  The follow table is an example of an access matrix for different users access
-  to a specific resource.
+    The follow table is an example of an access matrix for different users access
+    to a specific resource.
 
-  | user | read | write | execute |
-  | ---- | ---- | ----- | ------- |
-  | 1000 |  x   |       |    x    |
-  | 2000 |  x   |   x   |    x    |
-  | 3000 |  x   |       |         |
+    | user | read | write | execute |
+    | ---- | ---- | ----- | ------- |
+    | 1000 |  x   |       |    x    |
+    | 2000 |  x   |   x   |    x    |
+    | 3000 |  x   |       |         |
 
-  Access matrices makes it possible to define what types of operations different
-  domains can perform against different types of objects. The access matrix can
-  implement policy decisions related to protection.
+    Access matrices makes it possible to define what types of operations different
+    domains can perform against different types of objects. The access matrix can
+    implement policy decisions related to protection.
 
 1. How does a virus differ from a worm?
 
-  A worm is a process that duplicates itself to propagate across a network. They
-  are designed to use up system resources in order to reproduce itself so that
-  it can continue to infect other hosts.
+    A worm is a process that duplicates itself to propagate across a network. They
+    are designed to use up system resources in order to reproduce itself so that
+    it can continue to infect other hosts.
 
-  A virus is a fragment of code embedded in a legitimate program. Viruses can
-  also be self replicating but tend to target weaknesses in programs. They
-  can wreak havoc in a system by modifying or destroying files and causing
-  system crashes and program malfunctions.
+    A virus is a fragment of code embedded in a legitimate program. Viruses can
+    also be self replicating but tend to target weaknesses in programs. They
+    can wreak havoc in a system by modifying or destroying files and causing
+    system crashes and program malfunctions.
 
 1. What is the difference between symmetric encryption and asymmetric encryption?
 
-  Symmetric encryption relies on a single shared key for performing both the
-  encryption an decryption operations.
+    Symmetric encryption relies on a single shared key for performing both the
+    encryption an decryption operations.
 
-  Asymmetric encryption algorithms rely on each party having both a public and
-  private key. Public keys are exchange so that plaintext can be encrypted into
-  ciphertext using the other party's public key. Only that party can decrypt
-  the ciphertext back into plaintext using their private key.
+    Asymmetric encryption algorithms rely on each party having both a public and
+    private key. Public keys are exchange so that plaintext can be encrypted into
+    ciphertext using the other party's public key. Only that party can decrypt
+    the ciphertext back into plaintext using their private key.
 
-  Symmetric encryption and decryption operations tend to operate faster than
-  their asymmetric encryption counterparts. So many protocol will use asymmetric
-  encryption to perform the initial handshake to exchange a shared session key
-  to perform the remaining operations using the shared session key.
+    Symmetric encryption and decryption operations tend to operate faster than
+    their asymmetric encryption counterparts. So many protocol will use asymmetric
+    encryption to perform the initial handshake to exchange a shared session key
+    to perform the remaining operations using the shared session key.
 
 1. What are the two main varieties of authentication algorithms?
 
-  Message-authentication code (MAC) is a form of an authentication algorithm
-  that uses symmetric encryption. This algorithm generates a checksum using
-  the message data and key as input. On the receiving end the checksum and key
-  can be used to verify the authenticity of the data received.
+    Message-authentication code (MAC) is a form of an authentication algorithm
+    that uses symmetric encryption. This algorithm generates a checksum using
+    the message data and key as input. On the receiving end the checksum and key
+    can be used to verify the authenticity of the data received.
 
-  The second type of authentication algorithm is a digital signature.
-  Digital signatures utilize asymmetric encryption by encrypting a
-  digest of the plaintext data using their own private key. This allows the
-  receiving party to decrypt the digest using the senders public key to verify
-  the authenticity of the data.
+    The second type of authentication algorithm is a digital signature.
+    Digital signatures utilize asymmetric encryption by encrypting a
+    digest of the plaintext data using their own private key. This allows the
+    receiving party to decrypt the digest using the senders public key to verify
+    the authenticity of the data.