Chapter 6; Comptia gcga {Cryptography notes}
What does Perfect forward secrecy indicate
*THAT THE SYSTEMS DO NOT REUSE KEYS* That a cryptographic system generates random public keys for each session and it doesn't use a deterministic algorithm to do so. *It will create a different public key*
how many bits in HMAC-MD5
128 bit
Twofish
128 bit block cipher
What is Message Digest 5?
128 bit-hash, shown as hexadecimal, many files use this to verify the integrity of files.
how many bits in MD5
128 bits
How many keys does AES use?
128, 256 bit keys
How many bits in SHA-1
160 bit
how many bits in HMAC-SHA1
160 bit
How many bits in HSA-2
224,256,384,516
Blowfish
64 bit *block* cipher
What is a Hash
A number derived from performing a calculation on data, such as a message, patch, or update file.
AES,DES,3DES,Blowfish,Twofish,RC4
All Symmetric Encryption
What two things does Encryption normally need?
An algorithm and Key
What does Integrity provide
Assurances that data has not been altered
What is RSA
Asymmetric encryption method using both public and private keys, used to protect data in emails and other data transmitted over the internet.
What validates an identity?
Authentication
Quantum Cryptography
Based on quantum physics and photons.
______ ciphers encrypt data in blocks
Blocks
How does Encryption work?
By scrambling or ciphering data to make it unreadable if intercepted.
Analogous term for hash?
Checksum
What are MD5 and SHA
Common hashing algorithms
Two Diffie-Hellman methods that use ephemeral keys
DHE ECDHE
What does Confidentiality ensure?
Data is view able only be authorized users,
_____ ______ Provide authentication, non repudiation, and integrity
Digital Signatures
What is a certificate?
Digital document that includes the *public key* and information on the owner of the certificate.
What encryption method is commonly used with small wireless devices?
Elliptical Curve Cryptography
What hashing method uses fixed-length string of bits but also uses a shared secret key to add randomness and only the sender and receiver are aware?
HMAC
Are MD5, SHA-1, SHA-2, SHA-3, SHA-0 used for encrypting data?
Hell no ^^, they are hashing algorithms
What protocols use HMAC-MD5 and HMAC-SHA1?
IPsec and TLS
During Quantum Cryptography; when a third party reads any of the photons in the stream what happens.
It will be obvious to the two parties trying to exchange the key that there is someone eavesdropping.
Old windows based Hashing algorithm; backwards compatible
LANMAN
What prevents a party from denying an action
Non-Repudiation
Hashing is a _____ ____ ____ that creates a string of characters
One way function
Anything encrypted with the public key can only be decrypted with the matching _________- key
Private
Anything encrypted with the private key can only be decrypted with the matching _____- key
Public
RACE Integrity Primitives Evaluation Message Digest
RIPEMD
You cannot ______ the hash to re-create the original file
Reverse
Which SHA version is not used?
SHA-0
What are the four variations of SHA?
SHA-0, SHA-1, SHA-2, SHA-3
Symmetric Encryption
Same key to encrypt and decrypt
Waht is Diffie-Hellman
Secure method of sharing symmetric encryption keys over a public network.
RADIUS uses _____ ______ for symmetric encryption
Shared keys
Does RSA use static or ephemeral keys
Static
Two primary categories of asymmetric keys.
Static and Ephemeral
______ ciphers encrypt data one bit a time
Stream
RC4
Strong *symmetric stream* cipher
AES
Strong symmetric block cipher encrypts data in 128 bit blocks. 128 bit, 192 bit or 256 bit keys
What type of Encryption does RADIUS use?
Symmetric
Rootkits can modify what level files?
System-level
What does hashing ensure?
That data has retained integrity.
What does Encryption protect?
The confidentiality of data.
Asymmetric Encryption
Two keys; public and private/
How can you verify integrity?
With hashing
Web site encryption commonly uses a combination of
both asymmetric and symmetric encrryption
md5sum.exe
free application to calculate hashes
Although asymmetric encryption is very strong it is also very _____ ____
resource intensive
Hashes will always ____ _____ ____ no matter how many times you calculate it
stay the same
