Why is symmetric encryption weak

Graphic: Disadvantages of asymmetric encryption include slowness of execution when compared to symmetric encryption. So, in a nutshell, symmetric encryption is faster than asymmetric encryption. Asymmetric encryption sacrifices speed for security, while symmetric encryption sacrifices security for speed. Now, this is not to say that symmetric encryption is insecure; however, the very foundation of asymmetric encryption eliminates several information security risks that still exist within poorly managed symmetric encryption cryptosystems.

Graphic: Let's summarize the "key" differences between symmetric and asymmetric encryption. The key differences between symmetric and asymmetric encryption are speed and security preferences.

Generally speaking, symmetric encryption is faster and simpler but is often viewed as less secure than asymmetric encryption. But as we've discussed, encryption really boils down to two things: key size and the security of the media storing encryption keys.

Symmetric encryption is much faster to execute because of its shorter key lengths. Asymmetric encryption has a tendency to bog down networks because of its longer key lengths and complex algorithms. These are the tradeoffs worth considering when deciding which type of encryption to employ. For more information about how we ensure the integrity of your data using data encryption, reach out to us today.

Blogs by Trenton Systems. Symmetric vs. Asymmetric Encryption: What's the Difference? What is symmetric encryption? How does symmetric encryption work? What are some examples of symmetric encryption? What are some advantages of symmetric encryption? Some advantages of symmetric encryption include: Security : symmetric encryption algorithms like AES take billions of years to crack using brute-force attacks. Speed : symmetric encryption, because of its shorter key lengths and relative simplicity compared to asymmetric encryption, is much faster to execute.

Industry adoption and acceptance : symmetric encryption algorithms like AES have become the gold standard of data encryption because of their security and speed benefits, and as such, have enjoyed decades of industry adoption and acceptance.

What are some disadvantages of symmetric encryption? But is asymmetric encryption more secure than symmetric encryption? What is asymmetric encryption?

How does asymmetric encryption work? What are some examples of asymmetric encryption? What are some advantages of asymmetric encryption? Advantages of using asymmetric encryption include: Key distribution not necessary : securing key distribution channels has long been a headache in cryptography.

Asymmetric encryption eliminates key distribution entirely. The needed public keys are exchanged through public-key servers, and the disclosure of public keys is not, at this time, detrimental to the security of encrypted messages, because they cannot be used to derive private keys. Exchange of private keys not necessary : with asymmetric encryption, private keys should remain stored in a secure location and thus private to the entities using them.

The larger the key size the stronger the cipher. To understand the ramifications of insufficient key length in an encryption scheme, a little background is needed in basic cryptography. Basic Cryptography Background Cryptography is the process of converting ordinary information i.

This conversion process is called encryption. The second process of cryptography is called decryption which takes the ciphertext and recreates the plaintext. The key is used to cipher the plaintext and to decipher the ciphertext. Secure communications revolve around four basic components.

Encryption Algorithms for Data Exchange There are two basic types of encryption algorithms. One type uses a symmetric i. The other type uses asymmetric keys two keys are used; one key is a private key and one key is a public key.

The symmetric key encryption method uses the same secret key i. This method is fast and is typically used for data exchange. Symmetric encryption poses an initial session key exchange problem.

For example, How does each party securely exchange the same secret key value? This is accomplished by using the asymmetric encryption. The asymmetric method uses two keys:. The slower asymmetric encryption approach public key is distributed, private key is secret is used to start a secure communication session or tunnel. A symmetric session key is then generated and exchanged securely using the asymmetric encryption session or tunnel started earlier.

The subsequent data exchanges are then encrypted and decrypted using the faster symmetric algorithm, which uses the securely transmitted shared session key that was exchanged with the asymmetric algorithm. Authentication To prove that a piece of information comes from a certain individual the term used for this is non-repudiation or entity digital signatures are used. Asymmetric encryption is used to accomplish this. For example, Fred generates a private and public key.

Fred then gives the public key to Gloria. Fred then uses the private key to encrypt a data message and sends this to Gloria. This proves the message comes from Fred. This verification of identity is done during the initial setup of a secure communication process. Challenge strings in encrypted form are exchanged during secure communication negotiations to verify authentication of both parties.

The hash algorithm processes the message to be exchanged and produces a unique identifier. The hash identifier is always the same fixed size regardless of the amount of data being exchanged. This hash or message digest i. The hash value guarantees the integrity of the information without verifying the message content bit by bit. Typically one-way hashes are used i. Each secure endpoint calculates a hash value and compares it on both ends.

If the hash values match, the message has not been altered in transmit. Table 1 - Symmetric Key Algorithms. Table 2 - Asymmetric Key Algorithms.

Table 3 — Hash Algorithms. Grouping the four components together derives a complete cipher suite description. Table 4 presents a list of common ciphers and the individual components used.

Kerberos KRB5 is another form of computer network authentication that uses both symmetrical and asymmetrical approaches to encryption. The number presented after an algorithm is the key size in bits used. The cipher names themselves typically contain the types of algorithms used in each step. Table 4 — Common Ciphers. Export Ciphers Explanation From the previous definition of weak ciphers any encryption algorithm used that have key lengths less than are considered weak ciphers. The weak ciphers have been bolded in Table 4.

Note that no weak cipher is used in the shared session key exchanges. In this article, the second in a 3-part series on symmetric key encryption technology, we look at the development of symmetric key encryption algorithms and the range of algorithms available today along with their strengths and weaknesses, as well as the importance of crypto-agility.

Optionally, the key length can be reduced to bits by making two of the keys the same — this is sometimes called 2DES or 2TDEA; however, this is no faster and a bit key is no longer considered secure. However, even though a bit key is still considered to be strong, it is no longer recommended for new applications because it uses a small block size 64 bits.

Given the high volume of data stored or transmitted by modern systems, this means having to change the key frequently, which is impractical. RC2 is a bit block cipher that supports a key length of up to bits, although it was initially only approved for US export with a bit key. RC4 is a stream cipher that has been very widely used e. However, neither RC2 nor RC4 are considered secure today. RC5 is a block cipher with a variable block size 32, 64 or bits , variable key length up to 2, bits and variable number of rounds up to This enables a trade-off between performance and security, and it is still considered secure when used with suitable parameters.

It was later modified to produce RC6 with a fixed block size of bits as a contestant for the Advanced Encryption Standard — see below. However, RC5 and RC6 are not widely used as they are patented. It is now commonly known as the AES algorithm, featuring a block size of bits and three key length options: , or bits. The number of rounds varies with key length. AES is the symmetric algorithm-of-choice for most applications today and is very widely used, mostly with or bit keys, with the latter key length even considered strong enough to protect military TOP SECRET data.

Note that, assuming there are no known weaknesses in an algorithm, a single bit key will take billions of years to brute force using any classical computing technology today or in the foreseeable future but see quantum computing below.