Every day, while sending an email, shopping online or logging into a bank, we use one of the oldest and most important fields of science that has become the invisible foundation of our digital lives - cryptography. It’s what makes it possible for us to securely communicate and conduct business on the global network, confident that our conversations, transactions and data are protected from unauthorized access.
To many managers and entrepreneurs, cryptography seems like an esoteric, mathematical field reserved for a handful of specialists. But in reality, understanding its basic principles and mechanisms is crucial today for making informed business decisions and managing risk in any modern company. This guide will explain in simple terms what cryptography is, how its key mechanisms, such as encryption and public keys, work, and why it is the absolute foundation of cyber security in your organization.
Shortcuts
- What is cryptography and why is it the foundation of modern digital security?
- What is the difference between symmetric and asymmetric encryption?
- How do public and private keys work in everyday applications such as e-mail or banking?
- Symmetric vs. Asymmetric Encryption
- How does cryptography ensure the confidentiality, integrity and authenticity of data?
- What is a hash function and what role does it play in storing passwords?
- How does the SSL/TLS certificate that we see as a “padlock” in the browser work?
- Are there encryption algorithms that are virtually impossible to break?
- What threat does the development of quantum computers pose to current cryptography?
- What are the best practices for managing cryptographic keys in a company?
- In what situations should a company absolutely use data encryption?
- Is encryption alone enough to ensure full information security?
- How do nFlo specialists use the latest cryptographic standards to ensure the security of our clients’ data and infrastructure?
What is cryptography and why is it the foundation of modern digital security?
Cryptography is the science of techniques and methods for securely transmitting and storing information in a way that prevents it from being read or modified by unauthorized persons. Its name comes from the Greek words kryptos (hidden) and graphein (to write), which literally means “secret writing.” The main purpose of cryptography is to ensure the confidentiality and integrity of data through the use of complex mathematical algorithms.
In practice, cryptography is the absolute foundation of modern digital security. Without it, our entire digital world as we know it could not exist. Every banking transaction, every conversation over an encrypted messenger, every login to a corporate system and every secure website (with a “padlock” in the address) bases its security on cryptographic mechanisms. It is this that allows secure authorization, identity verification and protection of data transmitted over a public, untrusted network such as the Internet.
Cryptography protects us from a wide range of threats. It prevents cybercriminals from eavesdropping on our communications, protects passwords stored in databases from being read in the event of a leak, and ensures that the document we receive actually comes from the declared sender and has not been altered along the way. In an era of increasing cyber attacks and regulations such as RODO that mandate data protection, the role of cryptography as an essential risk management tool is more important than ever.
📚 Read the complete guide: Ransomware: Ransomware - czym jest, jak się chronić, co robić po ataku
What is the difference between symmetric and asymmetric encryption?
Encryption is the basic cryptographic process of converting readable information (plain text) into an unintelligible form (ciphertext) using an algorithm and a key. There are two fundamental, different approaches to this process: symmetric and asymmetric encryption. Understanding this difference is key to understanding how modern security works.
Symmetric encryption is an older and conceptually simpler method. Its hallmark is the use of one and the same secret key for both the encryption and decryption processes of the data. Both sides of the communication (sender and receiver) must have the same key. It works a bit like locking a box with a padlock - the same key used to close it is needed to open it. Symmetric algorithms (such as the popular AES) are extremely fast and efficient, making them ideal for encrypting large amounts of data, such as entire hard drives or files. Their main drawback and challenge, however, is the secure distribution of the key. How do you transmit a secret key to a recipient in a secure manner when the communication channel can be eavesdropped?
Asymmetric encryption, also known as public key cryptography, solves this problem. This approach uses a pair of mathematically related keys: a public key and a private key. The public key, as the name implies, can be freely and publicly distributed - it can be posted on a website or emailed. The private key, on the other hand, must be guarded by its owner like the greatest secret. The magic is that data encrypted with a public key can only be decrypted with the corresponding private key. Asymmetric encryption (such as the RSA algorithm) is much slower than symmetric encryption, but ingeniously solves the problem of key distribution.
How do public and private keys work in everyday applications such as e-mail or banking?
Asymmetric cryptography, although it may sound complicated, is used by all of us every day, forming the basis of security for key digital services. Its two main uses are to ensure the confidentiality of communications and to digitally sign data to confirm its authenticity.
Imagine that we want to send a confidential e-mail to our business partner. To ensure that no unauthorized person can read it, we need to encrypt it. To do this, we ask the partner for his public key. Using this key, we encrypt the content of our message. From then on, the encrypted e-mail becomes impossible to read for anyone who does not have the matching private key. Even we, as the sender, are unable to decrypt it. The only person in the world who can do this is our partner, using his secret private key. This mechanism ensures confidentiality.
The second application is the digital signature, which works in reverse and is the foundation of electronic banking, among other things. When a bank sends us a transfer confirmation, it wants to give us a guarantee that it actually came from it and has not been altered along the way. To do this, the bank digitally “signs” this information by encrypting its hash (digest) with its private key. We, as recipients, can verify this signature using the bank’s publicly available public key. If we can decrypt the signature using the public key, we are mathematically certain that the message was signed with a matching private key that only the bank has. This ensures authenticity and integrity. In practice, the two mechanisms are often combined - for example, when establishing a secure SSL/TLS connection to the bank’s website.
Symmetric vs. Asymmetric Encryption
| Feature | Symmetric Encryption | Asymmetric Encryption |
|---|---|---|
| Keys | One secret key for encryption and decryption. | Key pair: public (for encryption) and private (for decryption). |
| Speed | Very fast. | Much slower. |
| Main application | Encryption of large amounts of data (files, disks, video streams). | Secure key exchange, digital signatures, authentication. |
| The biggest advantage | Performance. | It solves the problem of secure key distribution. |
| The biggest challenge | Secure transfer of the recipient’s secret key. | Computational complexity. |
| Popular algorithms | AES, 3DES, ChaCha20 | RSA, ECC (elliptic curve cryptography). |
How does cryptography ensure the confidentiality, integrity and authenticity of data?
Cryptography is the primary tool that enables the three fundamental goals of information security, known as the CIA security triad: Confidentiality, Integrity and Authenticity, to which Non-repudiation is also often added.
Confidentiality is ensured by the encryption process. As described earlier, converting readable information into unintelligible ciphertext using a key ensures that even if the data is intercepted by an unauthorized person, it will be worthless to him. Both symmetric encryption (used, for example, to encrypt the contents of a hard drive) and asymmetric encryption (used to secure e-mail communications) serve the same purpose - to protect information from unauthorized reading.
Integrity, or the assurance that the data has not been altered along the way, is mainly realized through hash functions and digital signatures. The hash function creates a unique, short “fingerprint” for any set of data. If the recipient calculates the hash from a received message and compares it with the hash calculated by the sender, he can be sure that the message has not been modified. A digital signature goes a step further - the sender encrypts this digest with his private key, further guaranteeing that it actually came from him.
Authenticity, or confidence in the identity of the sender, is also provided by digital signatures. Since only the owner of a private key can create a signature that can be verified with the corresponding public key, the successful verification of a signature is mathematical proof of its authenticity. Undeniability also comes from this mechanism - a sender who has digitally signed something cannot later deny the fact, just like a handwritten signature on a paper document.
What is a hash function and what role does it play in storing passwords?
A hash function is a fundamental cryptographic algorithm that, for any sequence of input data (e.g., a file, a message, a password), generates a fixed-length result called a hash value, hash or “fingerprint.” This process is unidirectional, meaning that it is virtually impossible to reconstruct the original input data from the hash value it has. Even the smallest change in the input data (e.g., changing one letter in a password) causes an exponential, complete change in the result.
These unique properties make hash functions (such as SHA-256 or SHA-3) play a key role in ensuring data integrity and, critically, in the secure storage of passwords. Storing user passwords in an open-text database is one of the worst and most dangerous practices. If such a database is leaked, all passwords immediately fall into the hands of criminals.
Therefore, instead of the password itself, only its hash value is stored in the database. When a user logs into the system, he or she enters his or her password. The system calculates the hash from the entered password and compares it with the hash stored in the database. If the two values are identical, the login is successful. In this way, even if a hacker steals the entire database, he will not know the original passwords, but only their hashes, from which passwords cannot be easily reconstructed.
To further increase security, a technique called “salting” (salting) is used. It consists in the fact that before calculating the hash, a random string of characters unique to each user is added to the original password (the so-called “salt”). Only such a combined string is hashed. This prevents the effective use of so-called “rainbow tables” - ready-made huge databases with calculated hashes for popular passwords, which could be used to quickly crack stolen shortcuts.
How does the SSL/TLS certificate that we see as a “padlock” in the browser work?
The distinctive “padlock” icon we see in the browser’s address bar next to the address of a website is a visual indication that our connection to that website is secured using the SSL/TLS (Secure Sockets Layer / Transport Layer Security) protocol. This protocol uses cryptographic mechanisms to ensure the confidentiality and integrity of the data transmitted between our browser and the server. The key element of this system is the SSL/TLS certificate.
An SSL/TLS certificate is a small data file that acts as a digital “ID card” for an Internet server. It contains several key pieces of information: the name of the domain for which it was issued, the server’s public key, and the digital signature of a trusted third party, the Certificate Authority (CA), such as Let’s Encrypt, DigiCert or Comodo. The role of the Certification Authority is to verify that the certificate applicant actually owns the domain in question.
When our browser connects to an HTTPS-secured page, the server sends it its SSL/TLS certificate. The browser then performs several actions. First, it verifies that the digital signature on the certificate is valid and was issued by a trusted Certificate Authority (browsers have a built-in list of trusted CAs). Second, it verifies that the domain name in the certificate matches the address of the site you are connecting to. If both of these verifications pass, the browser is assured that it is connecting to an authentic server and not a fake site impersonating it.
Once the certificate has been successfully verified, the browser uses the server’s public key (contained in the certificate) to securely, encrypt a secret symmetric key with the server. This symmetric key will then be used to encrypt all further communication (because it is much faster). In this way, thanks to the certificate and the mechanisms of asymmetric and symmetric cryptography, a secure, confidential and authenticated connection is established, symbolized just by the padlock icon.
Are there encryption algorithms that are virtually impossible to break?
Yes, modern cryptography is based on algorithms that, with the current state of knowledge and the available computing power of classical computers, are considered practically impossible to break. However, it is necessary here to distinguish between theoretical and practical impossibility.
The only algorithm that is theoretically impossible to break is the so-called One-Time Pad (OTP) key cipher. It involves the use of a fully random key that is at least as long as the encrypted message itself and is used only once. If these conditions are met, the ciphertext contains absolutely no statistical information about the plaintext, making it mathematically unbreakable. Its disadvantage, however, is the great difficulty in practical application, especially in the secure generation and distribution of such long, one-time keys.
All other commonly used algorithms, such as AES (Advanced Encryption Standard) for symmetric encryption or RSA and ECC (Elliptic Curve Cryptography) for asymmetric encryption, are not “unbreakable” in the theoretical sense, but are computationally secure. This means that the best known way to break them is through a brute-force attack, that is, testing all possible keys. With the right key length, the number of combinations is so astronomically large that it would take the world’s most powerful supercomputers billions of years to test them.
For example, for the AES algorithm with a key length of 256 bits, the number of possible keys is 2 to the power of 256. This number is greater than the estimated number of atoms in the observable universe. Therefore, unless some fundamental mathematical weakness is discovered in the algorithm itself, it can be considered virtually unbreakable using classical computers. The key to security, then, is the use of proven, standard algorithms and appropriately long keys.
What threat does the development of quantum computers pose to current cryptography?
The development of quantum computers poses one of the biggest and most fundamental threats to all modern cryptography, on which the security of our digital world is based. The problem is that quantum computers, operating on the principles of quantum mechanics, are able to solve certain specific mathematical problems exponentially faster than classical computers. Unfortunately, the exact difficulty of these problems is what underlies the security of most of today’s public key algorithms.
The biggest threat is to asymmetric cryptography, i.e. algorithms such as RSA and ECC (elliptic curve cryptography). Their security is based on the fact that it is extremely difficult to decompose a large number into prime factors (in the case of RSA) or solve a discrete logarithm problem on an elliptic curve (in the case of ECC). Classical computers would need billions of years to do this. But Shor’s algorithm, which can be run on a sufficiently large and stable quantum computer, can solve these problems in hours or days. This means that when such computers appear, all of today’s public key cryptography, used in SSL/TLS certificates and digital signatures, among other things, will become immediately useless.
Interestingly, symmetric encryption, such as the popular AES algorithm, is much more resistant to quantum attacks. Although Grover’s algorithm allows some acceleration of brute-force attacks on symmetric algorithms, its impact is not so dramatic. To maintain the same level of security in the quantum era, simply doubling the key length (e.g., switching from AES-128 to AES-256) is a relatively simple change.
In response to this threat, cryptographers around the world are working intensively on a new generation of public key algorithms that would be resistant to attacks from both classical and quantum computers. This process, known as Post-Quantum Cryptography (PQC), is currently in the standardization phase, led by the US NIST, among others. The implementation of the new PQC standards will be one of the biggest challenges for the entire IT industry in the coming decade.
What are the best practices for managing cryptographic keys in a company?
Cryptographic keys are the heart of any encryption system. Even the strongest algorithm becomes useless if the keys that support it are stolen, lost or misused. That’s why cryptographic key management (Key Management Lifecycle) is one of the most important and challenging aspects of security in a company.
The basic principle is to minimize access to private keys and symmetric secret keys. They should be stored as securely as possible and accessible only to the minimum necessary number of people or processes. Instead of storing keys in configuration files on the server, dedicated, secure solutions such as Hardware Security Modules (HSMs) or specialized Key Management System (KMS) software should be used for this purpose. HSMs are specialized devices that generate and store keys in such a way that they cannot be exported, and perform all cryptographic operations inside their secure environment.
Another key practice is to rotate keys regularly. Cryptographic keys should not last forever. A policy should be implemented that specifies how often keys should be replaced with new ones (e.g., every year). This limits the potential damage in case the old key is ever compromised. However, the rotation process must be carefully planned so as not to cause service interruptions.
It is also necessary to maintain a detailed inventory of all cryptographic keys in use, recording what the key is used for, who owns it, its strength and when it expires. Procedures should also be implemented for the secure destruction of keys that are no longer needed. Finally, all key management operations (creation, rotation, deletion) must be logged and audited in detail to ensure full accountability.
In what situations should a company absolutely use data encryption?
While encryption is a good practice in many situations, there are scenarios where its use is not only recommended, but absolutely necessary from a security, compliance and risk management perspective. Ignoring encryption in these areas is tantamount to gross negligence.
First of all, encryption of data in transit (in-transit) is today a standard from which there are no exceptions. Any communication sent over public networks, especially over the Internet, must be encrypted. This applies to all corporate websites and web applications (mandatory HTTPS based on SSL/TLS), email connections (SMTPS, IMAPS, POP3S protocols), as well as remote access to the corporate network (mandatory use of VPN). Encryption in transit protects data from eavesdropping and Man-in-the-Middle attacks.
The second absolutely key area is data at rest (at rest) encryption on mobile and portable devices. All company laptops, smartphones, tablets, as well as external hard drives and flash drives on which any company data is stored must have whole-disk encryption enabled (e.g. BitLocker for Windows, FileVault for macOS). If such a device is stolen or lost, encryption is the only effective barrier to protect the data stored on it from unauthorized access.
Third, encryption is absolutely required for the storage and processing of sensitive and regulated data. This is especially true for personal data (according to the RODO, encryption is one of the key technical measures to minimize risk), financial data (according to the PCI DSS standard), business secrets and intellectual property. Encryption of databases, file servers and backups containing this type of information is a fundamental part of due diligence.
Is encryption alone enough to ensure full information security?
Definitely not. Encryption is an extremely powerful and absolutely essential tool in the cyber security arsenal, but it is not in itself a magical solution to all problems. Treating it as the only security measure is a dangerous oversimplification. Information security requires a comprehensive, multi-layered approach (defense-in-depth), in which encryption is just one, albeit very important, layer.
Encryption does an excellent job of protecting the confidentiality of data - preventing unauthorized people from reading it. However, it does not protect against many other attack vectors. For example, encryption will not protect a company from a ransomware attack, which also uses encryption, but against us. It won’t protect against a phishing attack, whereby an employee himself voluntarily gives his login information to criminals. Nor will it prevent malware infection, which can give a hacker full access to a system before the data is encrypted.
Moreover, the effectiveness of encryption depends on the security of the cryptographic keys. If the keys to an encrypted database are stolen, all security becomes useless. Therefore, in addition to encryption itself, strong access control, identity management (IAM) and secure key management mechanisms are crucial.
Full security requires combining encryption with other elements of a defense strategy, such as network protection (firewalls, IPS), endpoint protection (EDR), regular updates and vulnerability management, and, critically, building security awareness among employees. Only the interaction of all these layers - technical, process and human - can ensure a real, high level of information protection.
How do nFlo specialists use the latest cryptographic standards to ensure the security of our clients’ data and infrastructure?
At nFlo, we view cryptography as the foundation of all our cyber security services and solutions. We understand that in today’s threat landscape, the use of strong, modern and properly implemented cryptography is a prerequisite for real protection of our customers’ data and infrastructure. Our approach is based on expertise, best practices and the latest proven standards.
When designing and implementing secure networks for our customers, we always implement encryption of communications based on the latest and most secure protocols. When configuring corporate VPN solutions, we recommend and implement protocols such as WireGuard® or OpenVPN using strong ciphers (such as AES-256). When securing company websites and applications, we ensure that SSL/TLS certificates are properly configured and that the latest versions of the protocol (TLS 1.3) are enabled to protect data transmitted between client and server.
As part of our consulting and auditing services, we pay particular attention to evaluating the cryptographic mechanisms used by the client. We verify that sensitive data at rest (on servers, laptops, databases) is properly encrypted. We analyze cryptographic key management processes, recommending the implementation of best practices, such as regular key rotation or the use of HSM modules. During penetration testing, we actively look for weaknesses in cryptography implementations that could allow security bypasses.
We also stay abreast of the latest trends and threats, including developments in post-quantum cryptography (PQC). We advise our clients on how to prepare their organizations for the coming era of quantum computers, planning a long-term strategy for migrating to new quantum-proof standards. When you work with nFlo, you get the assurance that your security is built on a solid, modern and professionally managed cryptographic foundation.
Related Terms
Learn key terms related to this article in our cybersecurity glossary:
- Ransomware — Ransomware is a type of malicious software (malware) that blocks access to a…
- Network Security — Network security is a set of practices, technologies, and strategies aimed at…
- Wireless Network Security — Wireless network security refers to the measures and practices used to protect…
- Virtual Private Network — Virtual Private Network (VPN) is a network technology that creates a secure,…
- Cybersecurity — Cybersecurity is a collection of techniques, processes, and practices used to…
Learn More
Explore related articles in our knowledge base:
- What is a Man in the Middle (MITM) Attack and How Does It Work?
- Obfuscation - Code obfuscation - What is it, how does it work and how to detect it?
- What is CORS (Cross-Origin Resource Sharing) and how does it work?
- What is FIDO2 and how does modern authentication work?
- What is HSTS (HTTP Strict Transport Security) and how does it work?
Explore Our Services
Need cybersecurity support? Check out:
- Security Audits - comprehensive security assessment
- Penetration Testing - identify vulnerabilities in your infrastructure
- SOC as a Service - 24/7 security monitoring
Cybersecurity for Your Industry
Learn more about cybersecurity in your industry:
