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54 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Scytale |
Cryptographic Technique functioned by wrapping a strip of papyrus or leather around a rod of fixed diameter on which a message was written |
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Caesars Cipher |
Cryptographic Technique worked by means of simple substitution. (ROT3) Rotatated by three characters. |
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Cryptographic Goals |
(PAIN) Privacy Authentication Integrity Non-repudiation |
(PAIN) |
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Privacy |
Also called confidentiality. What is private should stay private, whether at rest or in transit |
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Authentication |
Proof that the message is from the person or entity we believe it to be from |
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Integrity |
Information should remain unaltered at the point it was produced, while it is in transmission, and during storage. |
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Non-repudiation |
The sender of the data is provided with proof of delivery and the recipient is assured of the senders identity. |
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Plain text |
Clear text that is readable |
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Cipher Text |
Encrypted text that is unreadable. |
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Encryption |
Transforming data into a unreadable format. |
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Cryptanalysis |
The act of obtaining plain text from cipher text without a cryptographic key. |
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Digital Signature |
A hash value that has been encrypted with the private key of the senders. (Authentication and Integrity) |
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Chain of Trust |
The relationship between subordinate certificate authorities. |
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Root of Trust |
Concept of Trust in a system, software, or data. |
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Attestation |
Validating something as true. |
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Trusted Platform Module (TPM) |
Most common form of Root of Trust. Defined by the endorsement key (EK) pair. |
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Symmetric Cryptography |
Uses single private key. |
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Asymmetric Cryptography |
Uses two keys: Public key: know to everyone Private key: only recipient uses. |
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Hash |
Mathematical procedure or function that converts a large amount of data into a fixed small string of data or integer. |
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Algorithm |
Set of rules or ordered steps used to encrypt and decrypt data. |
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Cipher Text |
Data that is scrambled and unreadable. |
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Block Cipher |
Function by dividing the message into blocks for processing. Common is 64-bit blocks |
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Stream Cipher |
Function by dividing the message into bits for processing. Inputs digits, bits, or characters and encrypts the stream of data. Combines the plain text bit with a pseudorandom cipher bit stream by means of an exclusive operation. (OR) (XOR) Higher speed than block cipher. Hardware implementation. |
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Cryptographic Key |
Used to control the transformation of plain text to cipher text and cipher text to plan text. |
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Entropy |
Randomness of the key. (Cryptographic Key) |
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Nonce |
Number used once. It is as random a number as a cryptographic system can generate. |
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Pseudorandom number generator |
Program that creates a (Nonce) . |
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Symmetric Encryption |
Faster than asymmetric.
Only provides Confidentiality. Difficult key distribution. Must operate out of band Uses a single shared key for encryption and decryption. |
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Asymmetric Encryption |
Easy key exchange Confidentiality and Authentication Slower than symmetric Used only to move small amounts of data. |
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Transposition Cipher |
Type of Block Cipher that shifts units of plain text in a consistent way so that the cipher text constitutes a permutation of the plain text. |
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Block Cipher Functions |
Substitution Transposition Confusion Diffusion |
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Substitution |
Block Cipher Function Functions by putting into thing in the place of another. |
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Transposition |
Type of Block Cipher Scrambles a message by reordering the plain text in some definite way. |
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Confusion |
Type of Block Cipher Uses a relationship between the plain text and the key that is so complicated an attacker can't alter the plain text and determine the key. |
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Diffusion |
A change in the plain text results in multiple changes spread throughout the cipher text. |
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Substitution Box (s-box) |
Technique used to introduce confusion. Designed to defeat cryptanalysis. (Look up Table) |
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Symmetric Algorithms |
(DES) Data Encryption Standard Advanced Encryption Standard Blowfish (CAST) Carlisle Adam's/Stafford Tavares (IDEA) International Data Encryption Algorithm Rijndael RC4 RC5 (SAFER) Secure and Fast Encryption Routine Skipjack Twofish |
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Data Encryption Standard (DES) |
Was once the most common algorithm used. All DES has been replaced by AES Developed by IBM Modified by NIST 64-bit block that princesses 64 bits of plain text at a time. Key size: 56-bits 8-bits Parity Checking |
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Advanced Encryption Standard (AES) |
Symmetric Algorithm replacement for (DES). Adopted from the Rijndael Algorithm. Used for sensitive and secret data. Key size: 128, 192, and 256 bits. |
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Blowfish |
Intended as a replacement for (DES) Variable block size Up to 448-bit key |
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Carlisle Adams/Stafford Tavares (CAST) |
Replacement candidate for (AES) 128 or 256-bit block cipher. |
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International Data Encryption Algorithm (IDEA) |
Block Cipher that uses a 128-bit key to encrypt 64-bit blocks of plain text. Used by Pretty Good Privacy (PGP) |
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Rijndael |
Block Cipher adopted as the (AES) by (NIST) to replace (DES) |
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Rivest Cipher 4 (RC4) |
Stream-based Cipher |
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Rivest Cipher 5 (RC5) |
Fast Block Cipher Supports: variable block size variable key size variable number of rounds Block Size: 32, 64, and 128-bits Key: Up to 2040 bits (ROUND) A sequential repetition of series of math functions. |
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Secure and Fast Encryption Routine (SAFER) |
Block-based cipher Processes data in blocks of 64 and 128 bits |
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Skipjack |
Block Cipher, promoted by the (NSA), uses an 80-bit key and operates on 64-bit blocks of text. |
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Twofish |
Block Cipher 128-bit block size Key: Up to 256-bits |
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Four Primary Operating Modes of (DES) |
(ECB) Electronic Codebook (CBC) Cipher Block Chaining (OFB) Output Feedback (CFB) Cipher Feedback |
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Electronic Codebook Mode (ECB) |
DES Mode of operation Default mode of encryption used by DES If the last block is not 64-bits, padding is added. Produces greatest throughput Easiest to Crack |
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Cipher Block Chaining Mode (CBC) |
DES Mode of operation Similar to ECB Inserts some of the cipher text created from the previous block into the next one. Process is called XORing |
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Output Feedback Mode (OFB) |
Implemented as a stream cipher, uses plain text to feed back into the stream of cipher text. |
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Cipher Feedback Mode (CFB) |
Implemented as a stream cipher and used to encrypt individual characters. |
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Triple DES (3DES) |
Designed to be a stopgap solution Certified on a five year basis Can use 2 or 3 keys to encrypt data. Key size: 112 or 168-bits 48 rounds of transposition and substitution Third the speed of 56-bit DES |
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