cryptography by Ahmad Fyqrie Bin Ahmad Rozley https://padlet.com/i21020133/qav0jh13drdvo2en en-us 2022-03-23 06:41:35 UTC 2022-03-30 07:36:29 UTC hello@padlet.com Symmetric Encryption i19017451 https://padlet.com/i21020133/qav0jh13drdvo2en/wish/2109113215 - is an old and best-known technique. 
- uses a secret key that can either be a number, a word or a string of random letters.
- is a blended with the plain text of a message to change the content in a particular way. 
- The sender and the recipient should know the secret key that is used to encrypt and decrypt all the messages.]]> 2022-03-23 06:45:09 UTC https://padlet.com/i21020133/qav0jh13drdvo2en/wish/2109113215 Topic i21020133 https://padlet.com/i21020133/qav0jh13drdvo2en/wish/2109116325 1.      MD5 - farid
2.      SHA - ahmad
3.      HMAC Hashing Algorithm - Kuan Bin
4.      Symmetric Encryption - desmond
5.      Asymmetric Encryption - desmond
6.      Diffie-Hellman - Ting Hang
]]> 2022-03-23 06:47:53 UTC https://padlet.com/i21020133/qav0jh13drdvo2en/wish/2109116325 Asymmetric encryption i19017451 https://padlet.com/i21020133/qav0jh13drdvo2en/wish/2109122533 - is also known as public key cryptography, which is a relatively new method, compared to symmetric encryption. 
- uses two keys to encrypt a plain text.
- Public key is made freely available to anyone who might want to send you a message. 
- Second private key is kept a secret.]]> 2022-03-23 06:54:06 UTC https://padlet.com/i21020133/qav0jh13drdvo2en/wish/2109122533 Asymmetric encryption vs Symmetric Encryption i19017451 https://padlet.com/i21020133/qav0jh13drdvo2en/wish/2109123398 2022-03-23 06:54:53 UTC https://padlet.com/i21020133/qav0jh13drdvo2en/wish/2109123398 SHA i21020133 https://padlet.com/i21020133/qav0jh13drdvo2en/wish/2109123764 - SHA stands for Secure Hashing Algorithm and it is a modified version of MD5 used for hashing data and certificates. 
- Hashing cannot be cracked unless brute force is used
- Hashing changes the word into a combination of letters and numbers


]]> 2022-03-23 06:55:07 UTC https://padlet.com/i21020133/qav0jh13drdvo2en/wish/2109123764 MD5 i19017436 https://padlet.com/i21020133/qav0jh13drdvo2en/wish/2109128014
- MD5 is a one-way cryptographic function that accepts any length message as input and produces a fixed-length digest value that may be used to authenticate the original message as output.
- originally designed as a cryptographic message authentication code algorithm for use on the internet.
- no longer reliable because MD5 collisions can occur with the commercial off-the-shelf computers
-encryption collision means two files have the same hash
]]> 2022-03-23 06:59:06 UTC https://padlet.com/i21020133/qav0jh13drdvo2en/wish/2109128014 Different forms of SHA i21020133 https://padlet.com/i21020133/qav0jh13drdvo2en/wish/2109128788 There are 2 general types of SHA: SHA-1 and SHA-2

The difference between SHA-1 and SHA-2 is that SHA-1 only return a 160-bit hash and it can be more easily brute-forced than SHA-2. SHA-2 gives every hash digest a unique value to make it more secure.

Subtypes of SHA are: SHA-256, SHA-512, SHA-224 and SHA-384 

The larger numbers are just versions of SHA-2 that note the bit lengths. Basically, the number defines the bit-lengths of the hashed digest.]]> 2022-03-23 06:59:55 UTC https://padlet.com/i21020133/qav0jh13drdvo2en/wish/2109128788 HMAC Hashing Algorithm jamespoon5517 https://padlet.com/i21020133/qav0jh13drdvo2en/wish/2109131395 - HMACs are created by combining a cryptographic hash function with a secret key in any cryptographic technique.
- Input data and the secret key are both used to determine the hash function's output, which can only be known by the sender and recipient.
- The digest of an HMAC function can only be computed by parties that have access to the secret key.
- A correctly built HMAC digest of a message received by one party shows that the other party was the sender if the parties have a shared secret key and employ HMAC functions to authenticate.]]> 2022-03-23 07:02:12 UTC https://padlet.com/i21020133/qav0jh13drdvo2en/wish/2109131395 is MD5 secure? i19017436 https://padlet.com/i21020133/qav0jh13drdvo2en/wish/2109136712 it used to be secured because of two reasons:-

- It is impossible for an attacker to generate a message matching a specific hash value.

- It is impossible for an attacker to create two messages that produce the same hash value.

But it is no longer secure methods according to IETF]]> 2022-03-23 07:07:14 UTC https://padlet.com/i21020133/qav0jh13drdvo2en/wish/2109136712 How HMAC Works jamespoon5517 https://padlet.com/i21020133/qav0jh13drdvo2en/wish/2109143479 - HMACs give the client and the server a shared private key that is only known to them. 
- Every time a request comes in, the client generates a new hash (HMAC). When a client makes a request to the server, the requested data is encrypted using a private key and sent along with the request. 
- Separate procedures are used to hash the message and the key, ensuring the integrity of the data being sent between the two. 
- As soon as the server accepts a request, it generates its own HMAC. The HMACS are compared, and if they are the same, the client is deemed authentic.]]> 2022-03-23 07:13:06 UTC https://padlet.com/i21020133/qav0jh13drdvo2en/wish/2109143479 Diffie-Hellman i20019629 https://padlet.com/i21020133/qav0jh13drdvo2en/wish/2109152008 The Diffie-Hellman key exchange was one of the most important developments in public-key cryptography
-safely developing and exchanging keys over an insecure channel.
-securely exchanging cryptographic keys over a public communications channel.
-This key can then be used to encrypt subsequent communications using a symmetric-key cipher.

To encode your messages, every “a” becomes  “b”, every “b” becomes “c”, every “c” becomes “d”, and so on, all the way up to the “z” becoming an “a”.
As a result, the message “Let’s get dinner” becomes “Mfu’t hfu ejoofs”.


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