Contact Us Today 01642 716680


Definition: Ciphertext is the unreadable output of an encryption algorithm, resulting from the process of transforming plaintext into a scrambled form using a cryptographic key.

Ciphertext is a fundamental concept related to the process of encryption, which is the cornerstone means of securing data. When data is encrypted, it is converted from its original readable form, known as plaintext, into a garbled format that hides its substance from anyone who does not possess the appropriate key to decrypt it back to plaintext. The strength and integrity of the ciphertext are reliant upon the encryption algorithm used and the secrecy of the encryption key.

This transformation is crucial for protecting sensitive information during storage and transmission, especially across insecure or public networks. It ensures that even if an unauthorised party intercepts the data, they cannot understand it without the key. The ciphertext should be sufficiently random and indistinguishable from random noise so that potential attackers cannot derive any meaningful patterns from it.

The use of ciphertext is widespread across various forms of secure communications, digital identity verification, online transactions, and confidential data storage. Periodic advancements in cryptography and increases in computing power necessitate the continuous evolution and evaluation of encryption methods to ensure that ciphertext remains secure against increasingly sophisticated methods of cryptanalysis.

Key Characteristics:

  • Encoded information unreadable without decryption key
  • Result of applying an encryption algorithm to plaintext
  • Crucial for data security and privacy
  • Dependent on algorithm strength and key secrecy


  • Real-World Example: A user sends a message over an encrypted messaging app. The app encrypts the message to ciphertext using an encryption key before sending. On receipt, the recipient’s app uses a corresponding decryption key to convert it back to plaintext.
  • Hypothetical Scenario: A company stores sensitive customer data. When saved to the database, the data is converted to ciphertext using an advanced encryption standard (AES) algorithm, rendering it unreadable without the necessary decryption key.

Related Terms:

  • Plaintext: The original, readable form of data before being encrypted into ciphertext.
  • Encryption Key: A piece of information (a key) that determines the functional output of a cryptographic algorithm during the encryption and decryption processes.
  • Cryptanalysis: The study and practice of analysing information systems to breach cryptographic security systems and gain access to the underlying data, specifically targeting ciphertext to uncover plaintext.
  • Encryption Algorithm: A mathematical procedure converting plaintext to ciphertext and vice versa.

Related Services:

What is the OWASP Top 10: Download our flash cards to find out.

Inside you will find a description of the most common web vulnerabilities.

Contact us

Get a free, no obligation quote from one of our expert staff.