Cryptography Flashcards
how does the Caesar cipher encrypt messages?
by moving the alphabet to the left or right by a certain number of places. the direction and number of places moved is called the ‘key’
what is the key used for?
to decrypt the messages by moving the alphabet the same number of places, but in the opposite direction
what is the layout of the Caesar cipher?
the decrypted letters are on top and the encrypted messages are on the bottom. it is the decrypted letters which move to the right or left
what is a barcode?
a series of bars and spaces that when read by a laser can be used to store details about a product. they use a series of numbers and a check digit to make sure the bars and spaces have not been damaged. the check digits are at the ends
what information does a bar-code store?
product identification
size/weight of product
where the product has come from
who manufactured the product
what does PGP stand for?
pretty good privacy
what does PGP involve?
2 keys: a public key and a private key
the 2 keys are asymmetric - they are the reverse of each other
what is the encryption process with PGP?
the public key can be used to encrypt anything and everyone can use it so that it is impossible to understand
what is the decryption process with PGP?
it only belongs to one person so only one person can decrypt it and it only decrypts the encrypted messages from the public key
