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31 Cards in this Set
- Front
- Back
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Symetric Encryption |
Also called Secret Key Encryption - Strengths - Fast, Difficult to Break, Cheaper than Asymetric Weakness - Needs to be secured properly, Complex Key Management, Does Not Provide Authentication |
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Asymetric Encryption |
Also called Public Key Encryption - Strengths - Separate keys public and private, Authentication and Non-Repudiation, Better scalability, slower |
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Symetric Encryption Algorithyms |
DES - Data Encryption Standard - now considered to be insecure for many applications
3DES - Triple Data Encryption Standard AES - Advanced Encryption Standard
Larger the number of bits, stronger the encryption |
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DES (Data Encryption Standard) |
64 bit block 56 bit key 8 parity bits ECB - Electronic Code Book CBC - Cipher Block Chaining Mode CF - Cipher Feedback Mode OF - Output Feedback Mode CM - Counter Mode
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Encryption based on 128 bit Lucifer Algorithm |
DES (Data Encryption Standard) |
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XOR (Exclusive OR) |
Compares 1's and 0's - Two of Same number (2 1's or 2 0's) = 0, Difference in numbers = 1. |
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ECB (Electronic Code Book) |
ECB or electronic code book takes a message, divides it into blocks, and then each of the individual blocks are encrypted. |
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Cipher Block Chaining Mode |
Cipher block chaining mode takes each block of plaintext and exclusive ORs it with the previous ciphertext block before it is encrypted. |
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Cipher Feedback Mode |
Cipher feedback mode makes a block cipher into a self-synchronizing stream cipher. |
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Output Feedback Mode |
Output feedback mode takes a block cipher and makes it into a synchronous stream cipher. Let's take a look at how it does this. It generates a key stream block or blocks, which are then exclusive ORed with the plaintext blocks. When this process is complete, you're left with the ciphertext. |
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Counter Mode |
Counter mode takes a block cipher and turns it into a stream cipher. It generates the next key stream block by encrypting in order values of a specific counter. |
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3DES (Triple Data Encryption Standard) |
Uses 3 56 bit keys - encrypts 3 times with 3 keys. Triple Data Encryption Standard is known to cause heavy performance issues and the transmission of the keys are deemed unsafe.
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4 Modes of 3DES (Triple Data Encryption Standard) |
DES-EEE3 - 3 keys used DES-EDE3 - Plain txt encrypted 1 key - encryption process, then encrypted with 3rd key DES-EEE2 - 1st,2nd,then 1st, DES-EDE2 - 1st & 3rd key used |
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3DES (Triple Data Encryption Standard) EEE3 Mode |
DES EEE3 uses three different keys for encryption. |
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3DES (Triple Data Encryption Standard) EDE3 |
DES EDE3 – the plaintext is encrypted with one key, goes through a decryption process with key two, and then is encrypted with key three. |
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3DES (Triple Data Encryption Standard) EEE2 |
DES EEE2 - Encryption occurs with the first key, and then it is encrypted with the second key, and then encrypts it with the first key once again. |
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3DES (Triple Data Encryption Standard) EDE2 |
DES EDE2 - uses only two keys, and the first and third keys are used for the encryption process. The second key, which is only the different key between the three of them, is used in the middle process for the decryption. |
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Encryption using 168 bit Key |
3DES (Triple Data Encryption Standard) Triple Data Encryption Standard is known to cause heavy performance issues and the transmission of the keys are deemed unsafe. |
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AES (Advanced Encryption Standard) |
Symetric Block Cipher Based on Rjindael Algorithim Key length & Block Size - 128, 192, 256 bits 10-14 Computational Rounds 128 bits - 10 rounds, 192 bits - 12 rounds, 256 bits - 14 rounds |
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AES (Advanced Encryption Standard) Stages |
Add Round Key SubBytes ShiftRows MixColumns |
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AES (Advanced Encryption Standard) Advantages |
Can be implemented in wide range of processors, hardware, and environments Low Memory Requirements Defend against Timing Attacks 192 and 256 bits can provide high level of security |
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AES (Advanced Encryption Standard) Disadvantages |
Low number of computational rounds |
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Symetric Key Algorithms |
CCMP Rijndael CAST - 128 and 256 SAFER Blowfish - 64 bit block - key - 32 to 442 bits Twofish - 128 bit block - key 156 bits RC4 RC5 |
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CCMP |
Counter Mode Cipher Block Chaining Message Authentication Code Protocol. It's definitely a mouthful, but remember, it's an encryption protocol for wireless LAN protocols. |
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Encryption protocol for wireless LAN protocols. |
CCMP |
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Rijndael |
Rijndael was designed to replace the Data Encryption Standard algorithm. Like DES, it is a block cipher. But, unlike DES, it can use 128, 192, and 256-bit keys. |
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Designed to replace the Data Encryption Standard algorithm. |
Rijndael |
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CAST |
CAST is another symmetric key block cipher. There is CAST 128, which has been preceded by CAST 256. |
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SAFER |
SAFER stands for Secure And Fast Encryption Routine. |
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Blowfish |
Blowfish uses a 64-bit block size and has a variable key length, anywhere from 32 bits through to 448 bits. |
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Twofish |
Twofish uses a block size of 128 bits and key sizes up to 256 bits. |
