What Is Cryptography? Key Concepts for Cybersecurity Leaders

Why Cryptography Still Matters in 2025

Cryptography algorithms secure digital identities, transactions, communications, and infrastructure against tampering and prying eyes. As attackers grow more advanced and regulatory scrutiny intensifies, Chief Information Security Officers (CISOs) and employees alike must understand cryptographic fundamentals to manage risk and ensure compliance.

Cryptography protects data and underpins digital trust across identities, systems, and transactions. Ensuring proper cryptography is in use in your digital environments can also protect your organization against cybersecurity incidents that may require disclosure or leak sensitive data, such as Protected Health Information (PHI) or Personally Identifiable Information (PII).

What Is Cryptography?

Cryptography is the mathematical process of converting readable data (plaintext) into unreadable data (ciphertext) to protect confidentiality, integrity, and authenticity. The process only works if the intended recipient can decrypt it.

Cryptography serves four main goals:

• Confidentiality: Prevents unauthorized access to data
• Integrity: Ensures data hasn’t been altered
• Authentication: Verifies user or system identity
• Non-repudiation: Proves an action (like signing a transaction) occurred

Cryptography underpins secure internet traffic, digital identities, software updates, and financial systems.

Four Core Cryptographic Mechanisms

1. Symmetric Encryption

This method uses the same key to encrypt and decrypt data. It’s efficient and fast, especially for encrypting stored data or large volumes.

Examples:

• AES (Advanced Encryption Standard)
• DES (Data Encryption Standard)

Common use cases:

• File and database encryption
• Internal system communications

2. Asymmetric Encryption

Asymmetric encryption uses a public key to encrypt and a private key to decrypt.

Examples:

• RSA (named for its inventors)
• ECC (Elliptic Curve Cryptography)

Common use cases:

• Secure email and messaging
• Transport Layer Security (TLS) for HTTPS
• Virtual Private Networks (VPNs)
• Blockchain technology

3. Hash Functions

Hashing converts any input into a fixed-length string using a hashing algorithm. Hashes are one-way and cannot be reversed.

Examples:

• SHA-256
• SHA-3

Common use cases:

• Password
• Documents
• Messages

4. Digital Signatures

Digital signatures combine asymmetric encryption with hashing to verify the origin and integrity of data.

Common use cases:

• Financial transactions
• Secure document signing

Cryptography and Cybersecurity Frameworks

Frameworks like NIST Cybersecurity Framework (CSF), ISO/IEC 27001, and SOC 2 all strongly encourage or mandate cryptographic controls. Regulations such as GDPR, HIPAA, and PCI DSS also require or encourage strong cryptographic protections.

SecurityScorecard continuously scans for expired or weak TLS certificates in your digital footprint. These can be overlooked entry points for attackers.

Weak encryption is not just a technical issue, it’s a compliance risk.

Where Cryptography Is Used Today

Cryptography supports nearly every layer of modern IT infrastructure:

• TLS/SSL: Encrypts web traffic and underpins HTTPS, which makes it a more secure version of HTTP
• VPNs: Secures remote access to internal networks
• Email Encryption: PGP and S/MIME secure messaging
• Blockchain: Uses hashing and signatures to verify transactions

Common Cryptographic Attack Vectors

Misconfigured or outdated cryptography can leave your organization’s sensitive data, financial transactions, private communications and more at risk of exposure. Several top attack types include:

• Brute force attacks: Repeatedly guess encryption keys
• Man-in-the-middle (MitM) attacks: Intercept and modify traffic in transit
• Hash collisions: Exploit flaws in weak hashing algorithms such as MD5
• Padding oracle attacks: Attackers modify ciphertext to obtain the plaintext

Threat actors are constantly searching for the path of least resistance. If your encryption keys aren’t secured properly, for instance, bad actors can steal your keys and use them to generate legitimate authentication tokens and steal information. Artificial intelligence is also helping hackers to gain the upper hand and conduct attacks as well. Organizations must audit their cryptographic stack regularly, remove outdated algorithms (such as SHA-1, 3DES), enforce current standards, and stay up-to-date on threat intelligence to stay one step ahead of cybercriminals.

Cryptographic Best Practices for Security Leaders

• Use strong, modern encryption
• Enforce TLS 1.2 or higher, and disable SSL and older TLS versions
• Encrypt data at rest and in transit
• Rotate and manage certificates, as expired certificates are low-effort targets for attackers

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