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16 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Goals of cryptography |
P- Privacy( Confidentiality) A- Authentication I- Integrity N- Non-Repudiation |
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Cryptography |
Art of converting plain text to cipher Text
Cryptanalysis: Art of breaking the cipher
Cryptology: science of cryptography and cryptanalysis
Cryptosystem: implementation of code / cipher in hardware or software.
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Encryption |
Plaintext+Algorithm+key= cipher text |
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Zero knowledge proof |
Sharing a proof without sharing actual knowledge |
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Transposition cipher |
Rearranging the letters of plain text |
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Substitution cipher |
Replace each character or bit with different character |
E.g: vigenere cipher ( polyalphabatic cipher) |
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One time pads |
Key length should be equal to length of the message. Must be randomly generated Must be physically protected Must be used only once Types of substitution cipher( Vernam Cipher). |
Exam tip: when used properly , they are unbreakable) |
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Running cipher |
Where encryption key is equal to the length of the message. ( Key is chosen from a book or newspaper) |
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Monoalphabetic cipher Polyalphabatic cipher |
Monoalphabetic cipher : use one alphabet Polyalphabatic cipher: uses two or more alphabets. |
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Kerckhoff's principle |
Only the key should be kept secret. Algorithm should be publicly known. |
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Confusion |
Hide the relationship b/w the cipher text and the secret key. Complication is substitution cipher. |
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Diffusion |
One change in plain text, change the cipher text in multiple ways. |
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Caesar Cipher |
Monoalphabetic rotation cipher. Key is no of places to shift in alphabet.
Exam tip: vulnerable to frequency analysis attack, that analyze the rate at which specific letter appears. |
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Vigenere cipher: |
Polyalphabatic cipher . Alphabets repeated 26 times in a vigenere square |
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Digital signature |
A hash value encrypted with a private key. Digitally signed messages assure the recipient that the message truly came from the claimed sender. It enforce Non-Repudiation. |
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Digital certificate |
Version of x.509 to which the certificate confirms
Serial number
Signature algorithm identifier Issuer name Validity period Subjects name Subjects public key
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