Securing TCP/IP Flashcards
What is cleartext
Unencrypted, readable data. Includes binary that a computer can read.
How does the encryption process work?
Binary > Cipher > Key > Algorithm
The key is different each time, and effects the Algorithm’s output.
An 8-bit key will produce an 8-bit length encryption key. How does this effect files that are bigger than 8 bits?
The encryption is simply repeated upon each group of 8 bits.
What is symmetric encryption?
When the key pairs can both encrypt and decrypt the data sent between them
What is block-cipher encryption?
It encrypts in specific lengths ( in bits)
If for example it encrypts 128-bits it will encrypt the first 128 bits using one encryption key, and then a different key for all subsequent 128-bit groups in the data.
What is a stream cipher?
Using a different key for each bit in the data.
What is a hash
Converting data into a fixed length data string. This is used to verify integrity of data.
What is SHA? and its number range
Secure hashing algorithm. The numbers in the names of each SHA is the bit length of the hash it creates.
224-256
What are some real world applications of SHA-256?
SSH, Bitcoin, IPsec
What is the process for digital signatures
Message > hash > encrypt with private key > Send to client >Client decrypts > Compares hash received to one stored in browser > Verified certificate.
This message will include the third party verification also.
What’s included in the hashed and encrypted message sent to a client during the certificate validation process?
Public key, certificate information, third-party signature.
Where are the list of certificate authorities held (client-side)
In your browser
What is an example of a location, action and temporal attribute?
Location, Mobile screen pattern lock, access only during a specific time of day.
When would you use a self-signed certificate?
Internal use
What is network access control?
Forcing policies and rulesets upon the machines within a business. Not being allowed to enter the network unless you’re fully up to date and in compliance with the business’ security criteria is an example of network access control.
What is ACL and three of its sub-models?
Access control list is a method of security used to define permissions among users when accessing resources.
Mandatory AC - Every resource is labled with a level of security clearance
Discretionary AC - The owner of the file, at their own discretion, decides who can access the file.
Role-based AC - Based on user groups
What is PPP and 3 of its traits
Point to point protocol. Used to connect an initiator to a PC with authentication. This uses usernames and passwords, which the initiator will send over to the authenticating PC. This only allows ONE connection to ONE PC.
-Username and pass
-Plaintext
-No hash
What is PAP? and what is it used in?
Password authentication protocol is the username and password process used in point to point protocol (PPP)
It was succeeded by MS CHAP, (MS challenge handshake protocol) that, while still doing plaintext, hashes its passwords for mild security.
What form of PPP is still used in dial-up today?
MS-CHAPv2
-Username and pass
-Hashing
-No encryption (though the radius server will do this instead)
What is the purpose of a NAS?
NAS are the gateways people must go through to reach the inside of an enterprise network. You connect to this over PPP. When you try to connect to a business network, you will send your authentication to the Network Access Server, which will then forward the information on to the RADIUS server, and send the result back to you once it has it.
What is PKI?
Public Key infrastructure is the method by which certificate authorities use intermediate and root certificate servers to provide authentication to servers.
Root CA servers will not directly provide certificates, as they contain sensitive information regarding how the certificate is made. Instead, an intermediate CA server will speak with the Root CA to get a stamp of approval, and then pass it to an issuing CA server.
What is NAC?
Network access control controls the access of devices on your network. It ensures that systems trying to gain access meet compliance requirements and are generally fit to be on the network without causing any issues.