Cryptography Flashcards
cryptography
- kryptos meaning hidden
- prefix “crypt” means hidden and suffix “graphy”
cryptography
protecting data by hiding it from anyone who isnt suppoed to see, access, or change it
broad umbrell aterm that encompasses both cryptography and cryptanalysis
cryptology
cyrptananlysis
figuring out how to access data without having necessary cryptographic key
applications of cryptography
secure communication, financial transactio, and protecting sensitive data
- understanding of different types of cryptography such as symmetric, asymmetric
- basic concepts of encryption, decryption, hashing, and digital signatures
fundamentals of cryptography
types of cryptography
- symmetric
- asymmetric
symmetric
- uses single key for bothe encryption and decryption
- muts be shared by all communicationg parties
asymmetric
- allows users to encrypt information using shared keys
- two keys’ encyrption and decryption
cryptosystem
structure consisting of a set of algorithms that converts plaintext to ciphertext to encode or decode messages securely
process by which a readable message is converted to unreadable form to prevent unauthorized parties from reading it
encryption
process of converting an encrypted message back to its original form
decryption
called as original message
plaintext
3 concepts of cryptosystem
- encyrption
- decryption
- plainytext
private key
- is a symmetric key
- use a single key for both encryption and decryption
- must be shared to all parties which can be a challenge in some situatiions
public key
asymmteric key that allows users to encrypt information using shred keys
when should symmteric encryption be used
due to better perfomance and faster speed, it is typically used fro bulk encyrption of large amounts of data for database encryption
how does symmetric encryption work
- message you want to encrypt plaintext)
- symmetric key algorithms
- shared key for you and your recipient that can encrypt and decrypt
- encrypted message no one can read
method used by Caesar to secretly communicate with his generals
Caesar cipher
is numbe of sequencer of steps that is used to convert plaintext information into ciphertext
cipher
how does asymmetric encryption work
- allows users to encrypt information using shared keys
- if you want to send a message over the internet but also dont want anyone but the intentedd recipient to see what youve written
is numbe of sequencer of steps that is used to convert plaintext information into ciphertext
how does asymmetric cryptography works
- algorithm starts process
- mathematical function generates key pair
asymmetric cryptography process
- registration
- lookup
- encrypt
- decode
- reply
registration
sender have connected with official entity that generated both public and private keys
lookup
sender scours a public-key directory for recipient public key information
encrypt
sender creates message, encrypts it with recipient public key and sends it
decode
recipient uses private key to unscramble message
reply
if recipient wants to respond, process moves in reverse order
pros of asymmetric encryption
- security
- transparency
- appearance
- one-way mathematical functions that takes an input of any length and produced a fixed-size output
- used to ensure data integrity and to verify the authenticity of digital signatures
hashing
advanced encryption standard (AES)
algorithm that uses same key to encrypy and decrypt protected data
Rivest, Shamir, Adleman
(RSA)
- based on public-key encryption technilogy
- public key cryptosystem for reliable data transmission
- pirmarily used for secure key exchange and digital signature
Message-Digest Algorithm 5
(MD5)
- widely used cryptography hash function that results in 128-bit hash value
- message digests represented by 32 bit hexadecimal numbers
Security Hash Algorith
(SHA)
- used for hashin data and certificate lies
- every piece of data produces a uniqe hash that is thoroughly non-deplicable by any other piece of data
Cryptographic Algorithms
- Advanced Encryption Security
- Rivest, Shadir, Adleman
- Message-Digest Algorithm 5
- Secure Hash Algorithm
digital signature
- electronic, encrypted, stamp of authentication on digital information such as email
- confirms that the information origincated from signer and has not been altered
- may also provide repudiation
- looks like a digital footprint
- secure documents, emails, files
electronic signature
- confirms intent of signing a document
- no identity validation
- vulnerable to tampering and man-in-the-middle attacks
- no encryption
- looks like an electronic copy of handwritten signature
- document verification
how digital signatures work
- use cryptography to creat eunique digital fingerprints for document verification and secure online transaction
- signer’s identity is verified by trusted third party, Certificate Authority)
secure cryptographic process allows digital signatures to assure
- authentication of document
- verification of signer’s identity by trusted service provider
- no tampering or forgery occurred after document was digitally signed
signer is confirmed as the signer
authenticity
the content has not been changed or tampered with since it was digitally signed
integrity
proves all parties the origin of the signed content
non-repudiation
- signatures in microsoft word are time stamped by secure time-stamp server under certain circumstances have the validity
notarization
