3DES is used as symmetric or asymmetric encryption?

I thought it was to generate random key, so how could it encrypt data?

Please help me with some details of 3DES. Thanks in advance.

I would not call Triple DES "symmetric" encryption (I will explain later). As to the question of symmetric/asymmetric, the usual distinction is between a symmetric and an asymmetric cipher.

For example, in a symmetric encryption one encodes a plaintext using a key, while for asymmetric one encodes a message using a key. Usually one expects that the two ciphers should be of different types. In this case, they use a symmetric, non-trivial key to encrypt, and an asymmetric, "public" key to decrypt.

Is 3DES symmetric or asymmetric?

Is this the point of the question or am I missing something?

No, it is not a requirement for DES3 encryption algorithm that it should be symmetric or asymmetric. To answer your question however, there are 4 different versions of DES3 algorithms defined in RFC 2459 (that's the Internet Engineering Task Force standard) -. DES3ENCRYPT and DES3DECRYPT - for encrypting (symmetric) and. decrypting (symmetric) ciphertexts in connection with Diffie-Hellman public-key encryption. You are required to use AES and 3DES functions from AES module for encryption/decryption. respectively to achieve "strong" and "stronger" security level and not for DES3. algorithms themselves. So you can use single function in AES module for whole set (or multiple instances of single function to get enough parallel. processing) to accomplish your requirements.

What are some examples of symmetric and asymmetric encryption?

I'll assume you mean "symmetric" encryption.

There are lots of symmetric-only ciphers. Let's pick the most obvious ones:

DES - The National Institute for Standards and Technology publishes a table with its main properties. The DES is symmetric-key encryption, which was used in a number of previous US federal systems including DIEHARD. However, the government realized it didn't do crypto well, so they reissued FIPS PUB 56. The new one has two improvements:

It uses a key length of 56 bits (instead of 64), which halves the amount of effort required to break it. If the key is 16 bytes long, then that's only two 4-byte keys per 16 bytes, which is easy enough to crack, even if the attacker is very motivated.

It's an AES implementation, which is more complex than DES and better at resisting attacks. DES is still a good cipher, but since it doesn't support longer keys (which would be required in some cases for greater security), it's not as useful for most uses. Triple DES - The successor to DES, the NIST recommended mode for new systems is called Triple DES. It uses the same underlying structure as DES (aka Rijndael), but uses three keys instead of just two. Triple DES requires much more key space than double DES. Because it's more secure, it's also required for some FIPS documents (though the government is still allowed to issue FIPS documents using other ciphers). The triple version is FIPS v2, and the standard defines what the algorithm should be in a few different tables.

An algorithm satisfying these conditions will be: 20-bytes long for the "inner round keys". 16-bytes long for the "mid round key", 16 for the "outer round keys", and 12 for the "final round key". The key and data must always be provided in pairs (either both provided, or only one). Since the key is shared by all three rounds, the mid and outer keys can be reused, but the inner key cannot. In practice, this means that if you create a key, you can use that key twice, though the final output will differ from what it would have been.

What is an example of asymmetric and symmetric encryption?

An asymmetric encryption algorithm is a cryptosystem which uses two different keys: a public key and a private key.

The public key can be made publicly available. The private key is known only to the owner of the encryption key. The owner can encrypt a message with the private key. This message can only be decrypted with the corresponding public key.

A symmetric encryption algorithm is one which has a single key for both encryption and decryption. The symmetric key algorithm is usually called AES or Rijndael. Symmetric algorithms are easier to use and secure, but they are not recommended for many applications because they can be easily broken by brute force attacks. Symmetric algorithms are generally used for storing passwords and session tokens.

Asymmetric encryption is used for secure communications. For example, Alice wants to send a message to Bob. She sends the message to Eve who has access to both Alice and Bob. Eve then intercepts the message. If the encryption is asymmetric, then it's possible to have Alice and Bob agree on a symmetric key which they use to encrypt the message and to decrypt it. Only they would know the key. It would be hard for Eve to guess the key.

The security of asymmetric encryption is based on the difficulty of breaking the public-key cryptography. As long as the public key remains secret, the message can be sent securely.

The following diagram shows how an asymmetric and symmetric algorithm can be combined. An asymmetric encryption algorithm is used to create the public key. The private key is used to decrypt the message. A symmetric algorithm is used to encrypt and decrypt the message.

Asymmetric and symmetric cryptography is often combined to make it more difficult for an attacker to obtain the private key. For example, a user can use a pass phrase to generate a private key which can be used to encrypt a message. The encrypted message can then be stored in a database. A symmetric algorithm is used to encrypt the password. This makes it harder for an attacker to obtain the password because she will need to guess the password in order to decrypt the message.

AES is the US government standard symmetric encryption algorithm. The encryption algorithm is described in the following sections. The algorithm is also available in the following reference implementation.

Symmetric Encryption. Symmetric encryption is usually more efficient than asymmetric encryption.

What is an example of a triple DES?

I know that a DES is a keyed hash function with 3 keys (K1, K2, and K3), and the definition of a triple DES is that the keys are concatenated, but what does the DES mean?

It is not clear which part you found unclear. The algorithm Triple DES is a generalization of the two-key DES standard. It consists of three separate DES keys, each one a. Block of data bits (a byte, block, octet, etc. These three keys are then passed through the same DES algorithm as a pair. But to form the final output the output of one key is "bounded". Or concatenated with the output of the other keys to produce. A longer key. The result is that it is almost impossible to recover the original triple DES key (from the. Output) without solving a hard problem in number theory. A triple DES key is used for securing data on storage devices such. As compact disks, tapes, memory chips, and other media. It also is often used in software for encryption and authentication of. E-mail and other network communications. The term "triple DES" comes from the use of DES three times. During each DES function. You can read more on Wikipedia or here.