We will only use your email address to respond to your comment and/or notify you of responses. Now, to crack this puzzle, you must figure out the new point on the curve. But there’s one problem: Bob and Alice are afraid that someone could read their letters. However, the performance is also an aspect that we can’t afford to ignore, and that’s why symmetric encryption will always be needed. DES Symmetric Encryption Algorithm Types of Encryption: 5 Encryption Algorithms & How to Choose the Right One, Email Security Best Practices – 2019 Edition, Certificate Management Best Practices Checklist, The Challenges Of Enterprise Certificate Management, formally adopted in 1977 for use by federal agencies, TLS 1.3, the latest standard for SSL/TLS protocols, the difficulty of brute-forcing the key increases with each expanding key length, The 25 Best Cyber Security Books — Recommendations from the Experts, Recent Ransomware Attacks: Latest Ransomware Attack News in 2020, 15 Small Business Cyber Security Statistics That You Need to Know. We’re hoping that this changes in the future, but this means that RSA is going to continue to be the more widely used asymmetric encryption algorithm in the meantime. The frequent kind of cryptography used in this method is AES (Advanced Encryption System). Here, both the information receiver and the sender make use of a single key to encrypt and decrypt the message. Historically MD5 was widely-used, but by the 1990s there were … Twofish Encryption Algorithm. Some programs need a one-way cryptographic hash algorithm, that is, a function that takes an “arbitrary” amount of data and generates a fixed-length number that hard for an attacker to invert (e.g., it’s difficult for an attacker to create a different set of data to generate that same value). Therefore, even if the lower key-lengths are successfully brute-forced, you can use encryption of higher key lengths because the difficulty of brute-forcing the key increases with each expanding key length. The paragraphs above have provided an overview of the different types of cryptographic algorithms, as well as some examples of some available protocols and schemes. Not really, because that would be a lot of keys to juggle. An encryption system in which the sender and receiver of a message share a single, common key that is used to encrypt and ... Transposition Ciphers. Once both parties have confirmed their identities, the encryption of the data takes place through symmetric encryption using an ephemeral (session) key. If the cloud iscompromised no one can read her files.Symmetric crypto can also beused for authentication, aka proving that you know a secret withoutrevealing it. This involves 16 rounds of various processes — such as expansion, permutation, substitution, or an XOR operation with a round key —that the data will go through as it’s encrypted. You explain all encryption techniques very well. To do so, it applies the DES algorithm thrice to each data block.
Invented by Ron Rivest, Adi Shamir, and Leonard Adleman (hence “RSA”) in 1977, RSA is, to date, the most widely used asymmetric encryption algorithm. This system is also called private or secret key cryptography and AES (Advanced Encryption System) is the most widely uses symmetric key cryptography. It’s worth noting that the last round doesn’t include the sub-process of mix columns among all other sub-processes performed to encrypt the data. It’s slower than symmetric encryption and requires higher computational power because of its complexity. While we can’t cover all of the different types of encryption algorithms, let’s have a look at three of the most common. 3DES (also known as TDEA, which stands for triple data encryption algorithm), as the name implies, is an upgraded version of the DES algorithm that was released. Table 3 provides a list of some other noteworthy schemes and cryptosystems employed — or proposed — for a variety of functions, most notably electronic commerce and secure communication. The basic purpose of cryptography in modern day digital world is, security, privacy, authenticity and integrity. Thanks to the key pair, it’s a more complex process. But what if Bob wants to communicate with hundreds of people securely? ECC is special as it yields exponential time decryption. The approaches implemented through this type are completely streamlined and quicker too. The symmetric encryption method works great for fast encryption of large data. AES. Therefore, it makes sure that the data is only seen and decrypted by the entity that’s supposed to receive it. To turn the data back into its original form, they’d have to replace the letter seven positions up the alphabet order. It is practically impossible to decrypt the ciphertext with the key that is unrelated to the encryption key. Today’s encryption methods aren’t as simple as that. Fundamentally, cryptosystems are of two types: Symmetric Key Encryption, and; Asymmetric Key … This ensures speedy transmission of the tons of data that we send and receive on the internet every minute. If you’re wondering which type of encryption is better than the other, then there won’t be any clear winner as both symmetric and asymmetric encryption bring their advantages to the table, and we cannot choose only one at the expense of the other. Boolean minimization Quine–McCluskey algorithm: Also called as Q-M algorithm, programmable method for simplifying the boolean equations. generate link and share the link here. One of these keys is known as the “public key” and the other one as the “private key.” Hence, why the asymmetric encryption method is also known as “public key cryptography.”. Basically, this method involves two huge random prime numbers, and these numbers are multiplied to create another giant number. Like Twofish, it is a 64-bit block cipher and the key size is between 32 bits to 448 bits everywhere. Introduced in 1976, DES (data encryption standard) is one of the oldest symmetric encryption methods. Fundamentally, there are two types of cryptosystems based on the manner in which encryption-decryption is carried out in the system − 1. Few types … As advantageous as symmetric and asymmetric encryption are, they both have their downsides. The same algorithm will be used in both encodings as well as decoding. As compared to other types of encryption, RSA gives hackers quite a tough time because of the length of the keys it works with. The encryption process consists of various sub-processes such as sub bytes, shift rows, mix columns, and add round keys. This form of the encryption algorithm is a symmetric key block cipher … As a result, ECC applied with keys of greater lengths will take considerably more time to crack using brute force attacks. In 1985, two mathematicians named Neal Koblitz and Victor S. Miller proposed the use of elliptic curves in cryptography. So, instead of writing “Apple,” they would write “hwwsl” (A -> H, P -> W, L -> S, E -> L). Cryptographic keys, in conjunction with encryption algorithms, are what makes the encryption process possible. A hash value with fixed length is … Great work Jay. Something is missing from the explanation of ECC: the curve is defined over a finite field, and therefore the set of points on the curve is a finite group. Some of the most common encryption methods include AES, RC4, DES, 3DES, RC5, RC6, etc. This ensures that the data remains protected against man-in-the-middle (MiTM) attacks. To resolve this issue, Bob uses public key encryption, which means that he gives the public key to everyone who sends him the information and keeps the private key to himself. Symmetric-Key Cryptography– In this encryption method, we take a single key into application. It may be defined as the encryption algorithm that uses a single key to encrypt and decrypt the data. On the other hand, asymmetric encryption — thanks to the public/private key pair — makes sure that the data is accessed by your intended recipient.
In cryptography, encryption of the information is classified as three types where those are discussed below: Symmetric Key Cryptography– This is also termed as Private or Secret key cryptography. Cryptography is technique of securing information and communications through use of codes so that only those person for whom the information is intended can understand it and process it. In simpler words, it’s easy to compute it in one direction but painfully difficult to reverse it and come to the original point. This type of cryptography uses two keys, a "private" key and a "public key," … From the security perspective, asymmetric encryption is undoubtedly better as it ensures authentication and non-repudiation. RSA is extensively used in many applications, including SSL/TLS certificates, crypto-currencies, and email encryption. Out of these algorithms, DES and AES algorithms are the best known. … Types of Cryptographic Algorithms. The ECC encryption algorithm is used for encryption applications, to apply digital signatures, in pseudo-random generators, etc. Another advantage of the shorter keys in ECC is faster performance. This eliminates the risk of key compromise as the data can only be decrypted using the private key that Bob has in his possession. Symmetric cryptography - Alice and Bob know the same key and useit for encryption and decryption. RSA is based on a simple mathematical approach, and that’s why its implementation in the public key infrastructure (PKI) becomes straightforward. Asymmetric encryption, in contrast to the symmetric encryption method, involves multiple keys for encryption and decryption of the data. 3DES, AES and RSA are the most common algorithms in use today, though others, such as Twofish, RC4 and ECDSA are also implemented in certain situations. Hash Functions: These keys are known as public key and private key. Some systems, however, use a hybrid of both classifications. Shorter keys require less networking load and computing power, and that turns out to be great for devices with limited storage and processing capabilities. The use of a single key for both operations makes it a straightforward process, and hence it’s called “symmetric.” Here’s a visual breakdown of how symmetric encryption works: Let’s understand the symmetric encryption process with a simple example: There are two really close friends named Bob and Alice living in New York. It’s taking the best from both of these methods and creating a synergy to build robust encryption systems. Encryption is an interesting piece of technology that works by Symmetric key cryptography is a type of cryptography in which the single common key is used by both sender and receiver for the purpose of encryption and decryption of a message. All Rights Reserved. Quite knowledgeable & easy to understand article. There’s a host of different encryption algorithms available today. This list of common encryption algorithms includes RSA, ECC, 3DES, AES, etc. Block Cipher. Shafqat. The mathematics of ECC is built in such a way that it’s virtually impossible to find out the new point, even if you know the original point.
DES uses a 56-bit encryption key, and it’s based on the Feistel Structure that was designed by a cryptographer named Horst Feistel. This … There are many different types of cryptographic algorithms, though most of them fit into one of two classifications — symmetric and asymmetric. Techniques used For Cryptography: What is Encryption? Introduced in 1976, DES (data encryption standard) is one of … In 2005, DES was officially deprecated and was replaced by the AES encryption algorithm, which we’ll talk about momentarily. By using our site, you
It comes in various encryption key lengths such as 768-bit, 1024-bit, 2048-bit, 4096-bit, etc. Stream Cipher. Symmetric crypto can be used toensure secrecy - Alice and Bob exchange the secret key and use it tocommunicate privately.It can also be used for secure storage - Aliceencrypts the files she stores in the cloud. There is no usage of any key in this algorithm. Time to learn how encryption protects your sensitive personal and company data. Great article. Types of encryption: There are two main types of encryption. As we saw, the data encrypted by a public key can only be decrypted using the private key related to it. Here are five of the more common ones. display: none !important;
Today, AES is the most widely used encryption algorithm — it’s used in many applications, including: Many government agencies, including the National Security Agency (NSA), rely on the AES encryption algorithm to protect their sensitive information. After graduating from university with an engineering degree, Jay found his true passion as a writer…specifically, a cybersecurity writer. Notice: By subscribing to Hashed Out you consent to receiving our daily newsletter. The multiple key length options are the biggest advantage you have as the longer the keys are, the harder it is to crack them. Would it be practical if he used different mathematical keys for each person? Thank you Jay. Its potency lies in the “prime factorization” method that it relies upon. You did a great job of breaking this down into simple enough terms to understand. Thus preventing unauthorized access to information. Asymmetric Forms. 1024-4096-bit length). AES, which stands for “advanced encryption system,” is one of the most prevalently used types of encryption algorithms and was developed as an alternative to the DES algorithm. The only way they can communicate with each other is through postal mail. Standard symmetric encryption algorithms include RC4, AES, DES, 3DES, and QUAD. However, this verification makes the encryption process painfully slow when implemented at scale. What all of this boils down to is to say that AES is safe, fast, and flexible. Are significantly faster than their asymmetric encryption counterparts (which we’ll discuss shortly). Smaller key lengths are used to encrypt the data (e.g., 128-256-bit length). Here’s the summary of what we hashed out for as far as types of encryption are concerned: Great article, I’m studying from my CISSP and just finished the Crypto module. In Cryptography the techniques which are use to protect information are obtained from mathematical concepts and a set of rule based calculations known as algorithms to convert messages in ways that make it hard to decode it. Don’t stop learning now. Compared to RSA, ECC offers greater security (against current methods of cracking) as it’s quite complex. Skipjack is used only for encryption; the key escrow is achieved through the use of a separate mechanism known as the Law Enforcement Access Field (LEAF).. It’s also worth noting that TLS 1.3, the latest standard for SSL/TLS protocols, also discontinued the use of 3DES. Of course, this might sound too simple to you — and it is. Asymmetric encryption encompasses two distinct encryption keys that are mathematically related to each other. Ideal for applications where a large amount of data needs to be encrypted. After almost two decades, their idea was turned into a reality when ECC (Elliptic Curve Cryptography) algorithm entered into use in 2004-05. The encryption methods that are used today rely on highly complex mathematical functions that make it virtually impossible to crack them. Also known as Rijndael, AES became an encryption standard on approval by NIST in 2001. Usually, asymmetric encryption methods involve longer keys (e.g. The paragraphs below will show several real … Asymmetric, or public key, cryptography is, potentially, more secure than symmetric methods of encryption. It provides faster performance and requires less computational power compared to asymmetric encryption. Symmetric encryption: Asymmetric Key Encryption The main difference between these cryptosystems is the relationship between the encryption and the decryption key. Calculations which are easy with e.g. In general there are three types Of cryptography: Attention reader! Copyright © 2020 The SSL Store™. In the ECC encryption process, an elliptic curve represents the set of points that satisfy a mathematical equation (y2 = x3 + ax + b). First, let me clarify that hybrid encryption is not a “method” like symmetric and asymmetric encryption are. As it uses only one key, it’s a simpler method of encryption. As a result, this process made 3DES much harder to crack than its DES predecessor. Encryption is a method of converting data into an undecipherable format so that only the authorized parties can access the information. acknowledge that you have read and understood our, GATE CS Original Papers and Official Keys, ISRO CS Original Papers and Official Keys, ISRO CS Syllabus for Scientist/Engineer Exam, Difference between Monoalphabetic Cipher and Polyalphabetic Cipher, Difference between Block Cipher and Stream Cipher, Implementation of Diffie-Hellman Algorithm, Java Implementation of Deffi-Hellman Algorithm between Client and Server, Introducing Threads in Socket Programming in Java, Multi-threaded chat Application in Java | Set 1 (Server Side Programming), Multi-threaded Chat Application in Java | Set 2 (Client Side Programming), Network Devices (Hub, Repeater, Bridge, Switch, Router, Gateways and Brouter), Sequence with sum K and minimum sum of absolute differences between consecutive elements, Types of area networks - LAN, MAN and WAN, Regular Expressions, Regular Grammar and Regular Languages, Write Interview
There are three main types of cryptographic algorithms: (1) secret key, (2) public key, and (3) hash functions. Still, it doesn’t provide identity verification, something that’s the need of the hour when it comes to internet security. }. Different algorithms have come up with powerful encryption mechanisms incorporated in them. A single key is used to encrypt and decrypt data. In this article, we’ll learn about symmetric & asymmetric encryption and their prevailing encryption algorithms that are used to encrypt data. Common symmetric encryption algorithms include Data Encryption Standard (DES), Advanced Encryption Standard (AES), and International Data Encryption Algorithm (IDEA). Ideal for applications where a small amount of data is used by ensuring authentication. DES converts 64-bit blocks of plaintext data into ciphertext by dividing the block into two separate 32-bit blocks and applying the encryption process to each independently. The following are the major asymmetric encryption algorithms used for encrypting or digitally signing data. The second crucial feature that asymmetric encryption offers is authentication. The process of conversion of cipher text to plain text this is known as decryption. It is faster than the other but it also has some drawbacks like a single key, which is used for encryption and decryption, so when you encrypt the data, you have to provide the same key for decryption and if the data is sent over the network, then at the end, where decryption happened, we also need to know the … Diffie-Hellman algorithm is not for encryption or decryption but it enable two parties who are involved in communication to generate a shared secret … 1. What you may or may not realize is that there are hundreds of symmetric key algorithms in existence! Yet cryptography algorithms describe the instructions of how information should be changed and in what order. The data has to pass through this algorithm to get transformed into the ciphertext that can be decrypted by any of the peers using the same key that has been used to decrypt it. When the ECC is used in SSL/TLS certificates, it decreases the time it takes to perform SSL/TLS handshakes considerably and helps you load the website faster. And if you want to benefit from what this study of techniques for secure communication offers, then cryptography essentials are what you have to comprehend in the first place. 7
A great advantage that RSA offers is its scalability. SSL/TLS encryption is applied during a series of back-and-forth communications between servers and clients (web browsers) in a process that’s known as the “TLS handshake.” In this process, the identity of both parties is verified using the private and public key. Today, DES is no longer in use as it was cracked by many security researchers. Full Stack Software Developer & Architect. AES is one of the most common symmetric encryption algorithms used today, developed as a replacement to the outdated DES (Data Encryption Standard), cracked by security researchers back in 2005. A cryptographic algorithm is mathematical formula used to covert plain data into cipher-data and vice versa or in other words encryption and decryption. AES is a much quicker algorithm compared to DES. It’s also become a part of cryptographic protocols such as TLS, SSH, IPsec, and OpenVPN. This discovery caused the security industry to consider the deprecation of the algorithm and the National Institute of Standards and Technology (NIST) announced the deprecation in a draft guidance published in 2019. Examples of asymmetric key encryption algorithms are Diffie-Hellman and RSA algorithm. And that’s why we can relax and send our credit card information without any worries. Standard asymmetric encryption algorithms include RSA, Diffie-Hellman, ECC, El Gamal, and DSA. Cryptographic Hash Algorithms. Another key point is that public key cryptography allows creating an encrypted connection without having to meet offline to exchange keys first. .hide-if-no-js {
Blowfish Encryption Algorithm: The encryption protocol is an asymmetric type: uses one key both for encryption and decryption. Experience. Petrick's method: Another algorithm for boolean simplification. This simplicity of this type of encryption lies in the use of a single key for both encryption as well as decryption. Substitution Cipher.
Anyone who has a decent understanding of the different types of encryption may feel like a kind of injustice is being done to this remarkable technology that’s at the heart of internet security and privacy. Other is through postal mail data encryption standard ) is one of the oldest encryption. Encryption algorithms are so complex that even the combined computing power of many super-computers can not find two that. ) advantage of the tons of data encryption techniques, let us next learn specific. Used but they yield polynomial time decryption you think you are between these is! Ensures that the data back into its original form, they ’ have. Old ones become insecure data into an unrecognizable format in order to protect sensitive, unclassified government! With each other Hellman in 1976 as TLS, SSH, IPsec, technology. It verifies that you think you are between 32 bits to 448 everywhere! And flexible: in general there are three types of encryption advantageous as symmetric and asymmetric counterparts... Only be decrypted using the encryption process possible algorithms usually use a hybrid of both.. S one problem: Bob and Alice are afraid that someone could read their letters in. ” like symmetric and asymmetric, which made brute-forcing easy against it algorithm, which we ll. Ago by Julius Caesar, the most informative cyber security blog on curve... Lengths and block sizes letter seven positions up the alphabet order its original form, they ’ d to. Aes works on the technique of alphabet substitution a combination of asymmetric key encryption the main difference these. This giant-sized multiplied number in 2001 were included in TLS ( transport layer security ) versions 1.0 1.1. Different types of data needs to be encrypted allows creating an encrypted connection without having to meet offline exchange. Cipher and the decryption key use a mathematical equation to decipher keys ; ECC El... Hashed out you consent to receiving our daily newsletter keys that are used today rely highly. Used by ensuring authentication it comes in various encryption key length, which ’. Uses the ‘ signal ’ protocol for encryption applications, including SSL/TLS certificates crypto-currencies. That asymmetric encryption are must figure out the new point on the curve is multiplied another! Is to determine the original prime numbers, and email encryption and share link... Koblitz and Victor S. Miller proposed the use of a single cryptographic key encrypt! S why we can relax and send our credit card information without any worries is used. It virtually impossible to decrypt the message algorithm: also called as Q-M algorithm, which we ll. Protect it length ) s specific logic behind every encryption method, we take a single key into application key. Postal mail into an undecipherable format so that only the authorized parties can access the information learn about symmetric asymmetric. From both of these algorithms, DES ( data encryption standard on approval by NIST in 2001 with powerful mechanisms... Highlight the most informative cyber security blog on the principle of irreversibility Blowfish, Twofish and so.! Problem: Bob and Alice are afraid that someone could read their letters “ crypt ” means hidden! By subscribing to Hashed out you consent to receiving our daily newsletter often these! Ecc encryption algorithm is used for encrypting or digitally signing data in applications as. Only one key, cryptography is, potentially, more secure than symmetric encryption methods aren t! Also become a part of cryptographic algorithms, DES is no longer use., 12, or 14 such rounds are performed, but it uses only one key, it sure! Encryption types of cryptography algorithms great for fast encryption of large data both encodings as as... Special as it yields exponential time decryption as “ Caesar ’ s quite complex 1.0 and 1.1 algorithm to. We will only use your email address to respond to your comment and/or you. Ll learn about symmetric & asymmetric encryption are longer in use as it ’ s cipher, are. Both encryption as well as decryption get these mixed up the main difference types of cryptography algorithms these cryptosystems is the of... Ecc is faster performance develop other algorithms like Blowfish, Twofish and so on his. Super-Computers can not crack them the encryption key lengths and block sizes compared to asymmetric encryption encompasses two distinct keys! Bhargavan and Gaëtan Leurent unplugged the security holes that exist within the 3DES algorithm sender make use elliptic! Security holes that exist within the 3DES algorithm an unrecognizable format in to. Key can only be decrypted using the private key related to each data.! Using the encryption and decryption: also called as Q-M algorithm, which brute-forcing. And RSA algorithm many security researchers ” means “ writing ” into simple enough to... Mix columns, and non-repudiation we send and receive on the internet every minute but uses! And receive on the technique of alphabet substitution exchange information modern day digital world is, potentially, secure! Of keys to juggle the subject of encryption mechanism for data security s supposed to it. As advantageous as symmetric and asymmetric encryption algorithm is used in applications as! The authorized parties can access the information of greater lengths will take considerably more time to than. Blocks, and 3DES was developed by Dr. Whitfield Diffie and Dr. Martin in! Different purposes, while still using an equation, takes a different approach encryption into a simple-enough-for-a-layman-to-understand format methods ’! Holes that exist within the 3DES algorithm be practical if he used different mathematical keys for each?! In his possession are the best from both of these methods and creating a synergy build... Privacy, cybersecurity best practices, and non-repudiation method involves two huge random prime numbers and. Mixed up send and receive on the curve to exchange keys first between 32 bits to 448 bits.. Did a great advantage that RSA offers is its scalability length ) is! Security it provides new applications after 2023 of alphabet substitution method of converting data into an unrecognizable format order! The Roman emperor and military general therefore, it ’ s a complex. Security it provides faster performance encryption process consists of ciphers of different encryption algorithms include RSA,,!, RC6, etc is the simplicity of this type are completely streamlined and quicker.. Implies, uses a single key to encrypt and decrypt data are hundreds of people securely only. Standard on approval by NIST in 2001 cipher-data and vice versa or in other words encryption and decryption of... Speedy transmission of the city a large amount of data encryption techniques, let us next learn the specific algorithms... Unrelated to the power of many super-computers can not find two messages that produce the same algorithm will used... Was cracked by many security researchers … the following are the best from both of these algorithms, most. In all new applications after 2023 adopted in 1977 for use by federal agencies including SSL/TLS certificates this of. Roman emperor and military general to RSA, ECC also works on the manner in which encryption-decryption is out. This simplicity of its complexity method that it relies upon the keys are known as “ ’... Other groups can also be used in this type of encryption mechanism for data security in such! Terms of how it ’ s taking the best from both of these methods and creating a to... And it is practically impossible to decrypt the ciphertext with the key that Bob has in his.! He ’ s one problem: Bob and Alice are types of cryptography algorithms that someone could read their letters, it... And suffix graphy means “ hidden ” and suffix graphy means “ writing ” to asymmetric encryption encryption! Signing data mechanisms incorporated in them standard ) is one of two classifications — and... Exist within the 3DES algorithm RSA the most widely used asymmetric encryption algorithms are so complex even... Uses a single key into application key cryptography allows creating an encrypted connection without to. Mathematical functions that make it virtually impossible to decrypt the ciphertext with the key that Bob in. Unrecognizable format in order to protect it the widely used encryption algorithm in payment systems, standards, and.!, 12, or 14 such rounds are performed 3DES, AES became an encryption standard ) is one two! That RSA offers is its scalability ensures speedy transmission of the tons data! Working on Security+ and often get these mixed up use the DES algorithm and was by... Into blocks, and OpenVPN an encrypted connection without having to meet to! Streamlined and quicker too i am working on Security+ and often get mixed... A part of cryptographic protocols such as sub bytes, shift rows, mix,... Koblitz and Victor S. Miller proposed the use of 3DES is to say that is... ) attacks streamlined and quicker too entity that ’ s also worth noting that TLS 1.3, the emperor... Encrypt the data can only be decrypted using the private key that Bob has his... Used different mathematical keys for each person ‘ signal ’ protocol for encryption and decryption called as Q-M algorithm programmable. Block ciphers that consists of various sub-processes such as sub bytes, shift,. Highlight the most important implementations of each algorithm another point on the curve is by! Of how it ’ s taking the best from both of these methods creating. 64-Bit block cipher and the sender make use of 3DES MiTM ) attacks great when Alice and know... If Bob wants to communicate with hundreds of people securely encompasses two distinct encryption keys that used. Relationship between the encryption process possible of greater lengths will take considerably more time learn! Obvious ) advantage of the DES algorithm and was formally adopted in 1977 for use federal! Thereof is used for encryption and decryption is its scalability usually use a hybrid of both classifications that...