With symmetric encryption, a single encryption key is used to encrypt all electronic communication. It changes data using a mathematical technique and a secret key, rendering a message unintelligible. Symmetric encryption is a two-way approach since the mathematical process is reversed when decrypting the message using the same private key. Other names for symmetric encryption are private-key encryption and secure-key encryption.
The two types of symmetric encryption are carried out using block and stream methods. Block algorithms are applied to electronic data blocks. Several different bit lengths can be changed at once using the secret key.
The key is then applied to every block after that. The encryption system waits for all of the blocks to arrive before storing the encrypted network stream data in its memory components. The length of time the system waits can result in a major security flaw and jeopardize the security of your data. Until the remaining blocks come, the method comprises shrinking the size of the data block and merging it with the information in earlier encrypted data blocks.
Feedback is used to describe this. Once received, the entire block is encrypted. On the other hand, stream algorithms arrive in data stream algorithms rather than being kept in the memory of the encryption system. This technique is safer because the data is not held on a disc or system without encryption in the memory components.
A single key is used to both encrypt and decrypt data with symmetric encryption. The parties involved share this key, password, or passphrase, and they are free to use it to encrypt or decrypt any messages they like. It converts plain text, or readable data, into unintelligible ciphertext, enabling secure communications to be sent over an insecure internet, making it a part of the public key infrastructure (PKI) ecosystem.
The Data Encryption Standard (DES), which uses 56-bit keys, Triple DES, which repeats the DES algorithm three times with different keys, and the Advanced Encryption Standard (AES), which is advised by the US National Institute of Standards and Technology for securely storing and transferring data, are some of the most popular symmetric cryptography algorithms.
Pros And Cons of Symmetric Algorithms
While symmetric encryption is an older kind of encryption, it is faster and more efficient than asymmetric encryption, which strains networks due to data capacity limitations and excessive CPU usage. Symmetric cryptography is commonly used for bulk encryption / encrypting massive volumes of data, such as database encryption, due to its superior performance and speed (relative to asymmetric encryption). In the case of a database, the secret key may be used to encrypt or decrypt data exclusively by the database.
Read Also: What is Clickjacking?
The following are some examples of where symmetric cryptography is used:
- Payment applications, such as card transactions require the protection of personally identifiable information (PII) to prevent identity theft and fraudulent charges.
- Validations to ensure that the message’s sender is who he says he is.
- Hashing or generating random numbers
Pros of symmetric algorithms
- Exceptionally safe
Symmetric key encryption can be highly secure when it employs a secure algorithm. As recognized by the US government, the Advanced Encryption Standard is one of the most extensively used symmetric key encryption schemes. Using ten petaflop machines, brute-force guessing the key using its most secure 256-bit key length would take about a billion years. Because the world’s fastest computer, as of November 2012, runs at 17 petaflops, 256-bit AES is virtually impenetrable.
One of the disadvantages of public-key encryption methods is that they require very complex mathematics to function, making them computationally intensive. It’s pretty simple to encrypt and decrypt symmetric key data, resulting in excellent reading and writing performance. Many solid-state drives, which usually are pretty fast, use symmetric key encryption to store data inside, yet they are still quicker than traditional hard drives that are not encrypted.
Because of their security and speed benefits, symmetric encryption algorithms like AES have become the gold standard of data encryption. As a result, they have enjoyed decades of industry adoption and acceptance.
- Requires low computer resources
When compared to public-key encryption, single-key encryption uses fewer computer resources.
- Minimizes message compromises
A distinct secret key is utilized for communication with each party, preventing a widespread message security breach. Only the messages sent and received by a specific pair of sender and recipient are affected if a key is compromised. Other people’s communications are still safe.
Cons of symmetric algorithms
- The Sharing of the Key
The most significant drawback of symmetric key encryption is that the key must be communicated to the party with which you share data. Encryption keys aren’t just plain text strings like passwords. They’re essentially nonsense blocks. As a result, you’ll need a secure method of delivering the key to the other party. Of course, you generally don’t need to use encryption in the first place if you have a secure mechanism to communicate the key. With this in mind, symmetric key encryption is particularly beneficial for encrypting your data rather than distributing encrypted data.
- If your security is compromised, you will risk more damage.
When someone obtains a symmetric key, they can decode anything that has been encrypted with that key. When two-way communications are encrypted by symmetric encryption, both sides of the conversation are vulnerable. Someone who obtains your private key can decode communications sent to you, but they won’t decipher messages sent to the other person because they are encrypted with a different key pair.
- The message’s origin and authenticity cannot be guaranteed
Because both the sender and the recipient have the same key, messages cannot be validated as coming from a specific user. If there is a disagreement, this might be a problem.
What Are The Advantages And Disadvantages of Symmetric And Asymmetric Encryption Algorithms?
Encryption is the process of converting data into an unintelligible format in order to safeguard its validity, confidentiality, and integrity. The mathematical formulas known as encryption algorithms specify how data is altered and how it might be returned to its original state. Symmetric and asymmetric encryption techniques are the two primary categories.
You can read about each type’s benefits and drawbacks as well as how file systems use them below.
Symmetric encryption uses the same key to encrypt and decrypt the data. The key is a secret value that both the sender and the receiver of the data must know and keep secure. Symmetric encryption is fast, efficient, and simple to implement. It is suitable for encrypting large amounts of data, such as files, disks, or databases. However, symmetric encryption also has some drawbacks. It requires a secure way to distribute and manage the keys among the parties involved.
If the key is compromised, the data can be easily decrypted by an unauthorized party. Moreover, symmetric encryption does not provide authentication or non-repudiation, which means that it does not verify the identity of the sender or prevent the sender from denying the message.
Asymmetric encryption uses two different keys to encrypt and decrypt the data: a public key and a private key. The public key is known to everyone and can be used to encrypt the data. The private key is known only to the owner and can be used to decrypt the data. Asymmetric encryption provides authentication and non-repudiation, as the sender can sign the data with their private key and the receiver can verify the signature with the public key.
It also allows secure key exchange, as the parties can use each other’s public keys to encrypt and share their symmetric keys. However, asymmetric encryption also has some disadvantages. It is slower, more complex, and more resource-intensive than symmetric encryption. It is not suitable for encrypting large amounts of data, as it requires more computation and storage space.
Hybrid encryption is a combination of symmetric and asymmetric encryption. It uses asymmetric encryption to exchange the symmetric keys and then uses symmetric encryption to encrypt and decrypt the data. Hybrid encryption combines the advantages of both types of encryption: it is fast, secure, and flexible.
It is widely used in file systems that need to support multiple users, such as cloud storage, email, or web applications. Hybrid encryption allows each user to have their own private key to decrypt their own files, while also enabling other authorized users to access the files with their own keys.
File system encryption
File system encryption is the application of encryption to the files and folders stored on a device or a network. File system encryption can protect the data from unauthorized access, modification, or deletion. File system encryption can be performed at different levels, such as full disk encryption, partition encryption, or file encryption.
Full disk encryption encrypts the entire disk, including the operating system, applications, and data. Partition encryption encrypts a specific section of the disk, such as a logical drive or a volume. File encryption encrypts individual files or folders, either manually or automatically.
Encryption standards are the specifications that define how encryption algorithms are designed, implemented, and tested. They are important for ensuring the security, compatibility, and interoperability of encryption systems. Various organizations, such as governments, industry associations, or academic institutions, can develop encryption standards. Examples of these include the Advanced Encryption Standard (AES), Rivest-Shamir-Adleman (RSA), Data Encryption Standard (DES), and Elliptic Curve Cryptography (ECC).
AES is a symmetric encryption standard that uses 128-bit, 192-bit, or 256-bit keys and supports various modes of operation. RSA is an asymmetric encryption standard that uses variable-length keys and is based on the difficulty of factoring large numbers. DES is an outdated symmetric encryption standard that uses 56-bit keys and is vulnerable to brute-force attacks. ECC is an asymmetric encryption standard that uses mathematical curves to generate keys and is more efficient than RSA.
Encryption is not a foolproof solution for data protection, as it faces several challenges that can affect its performance, usability, and security. These challenges include key management, encryption overhead, compatibility issues between different encryption systems, and attacks that may break the encryption or expose the keys. Key management involves generating, storing, distributing, and revoking keys, which is complex and requires proper policies and procedures.
Encryption overhead adds extra time and resources to the data transmission and processing. Different encryption systems may have different standards, formats, or protocols that may not work well together or with other applications. Lastly, encryption systems may be vulnerable to various types of attacks such as brute-force, side-channel, or cryptanalysis attacks.
What is the Biggest Problem With Symmetric Encryption?
The weakest point of symmetric Encryption is its aspects of key management.
- Key exhaustion In this type of Encryption, every use of a cipher or key leaks some information that an attacker can potentially use for reconstructing the key. To overcome this, the best way is to use a key hierarchy to ensure that master or key-encryption keys are never over-used and that appropriate rotation of keys is done.
- Attribution data Symmetric keys do not have embedded metadata for recording information which generally consists of an expiry date or an Access Control List for indicating the use of the key may be put to. This can be addressed by standards like ANSI X9-31, where a key is bound to information prescribing its usage.
- Key Management at large scale If the number of keys ranges from tens to low hundreds, the management overhead is modest and may be handled by human activity or manually. But, with a large estate, tracking keys’ expiration and rotation arrangement becomes impractical. So, special software is recommended to maintain the proper life cycle for each created key.
- Trust Problem It is very important to verify the source’s identity and the integrity of the received data. Suppose the data is related to a financial transaction or a contract, the stakes are higher then. Although a symmetric key can be used for verifying the sender’s identity who originated a set of data, this authentication scheme can encounter some problems related to trust.
- Key Exchange Problem This problem arises from the fact that communicating parties need to share a secret key before establishing a secure communication and then need to ensure that the secret key remains secure. A direct key exchange may prove to be harmful in this scenario and may not be feasible due to risk and inconvenience.
Symmetric Cryptography has proved to be the better choice when banking-grade security is considered for outbalancing all the disadvantages of asymmetric cryptography. Professional banking-grade key management systems will help compensate for the disadvantages of asymmetric cryptography and turn those into advantages.