Browse Definitions :
Definition

Alice and Bob

Alice, Bob and Eve are commonly-used names for participants in a scenario. The names can be found in a variety of contexts including cryptography, game theory and physics.

In 1978, professors Ron Rivest, Adi Shamir and Len Adleman (RSA) chose the names Alice and Bob to make it easier for people to understand how public key encryption works. Alice and Bob were chosen as placeholders for Person A and Person B to make the details easier to follow in a paper entitled "A Method for Obtaining Digital Signatures and Public-Key Cryptosystems." The names were intended to help people visualize how two entities could exchange information privately over an electronic mail system.

Alice and Bob are the best -known security scenario characters but there are many more used for various roles. For example, Eve is often used to represent an eavesdropper. For more complex requirements, the names Carol,  Carlos or Charlie may represent Person C and Dan or Dave a fourth participant, and so on through the alphabet sequentially as required. Other common characters from the large potential cast, include: Craig, a password cracker; Mallet or Malory (often abbreviated as Mal), a malicious attacker; Trudy, an intruder and Victor, a verifier.

Some of our definitions use Alice and Bob to help explain things. See: Diffie-Hellman key exchange, quantum cryptography, RSA algorithm

Alice and Bob and their co-characters are commonly featured in tech humor. The following example is from xkcd:

protocol

This was last updated in November 2015

Continue Reading About Alice and Bob

Start the conversation

Send me notifications when other members comment.

Please create a username to comment.

-ADS BY GOOGLE

File Extensions and File Formats

SearchCompliance

SearchSecurity

  • cybersecurity

    Cybersecurity is the protection of internet-connected systems, including hardware, software and data, from cyberattacks.

  • asymmetric cryptography (public key cryptography)

    Asymmetric cryptography, also called public key cryptography, uses a pair of numerical keys that are mathematically related to ...

  • digital signature

    A digital signature is a mathematical technique used to validate the authenticity and integrity of a message, software or digital...

SearchHealthIT

SearchDisasterRecovery

  • business continuity plan (BCP)

    A business continuity plan (BCP) is a document that consists of the critical information an organization needs to continue ...

  • disaster recovery team

    A disaster recovery team is a group of individuals focused on planning, implementing, maintaining, auditing and testing an ...

  • cloud insurance

    Cloud insurance is any type of financial or data protection obtained by a cloud service provider. 

SearchStorage

  • hard disk drive (HDD)

    A computer hard disk drive (HDD) is a non-volatile memory hardware device that controls the positioning, reading and writing of ...

  • byte

    In most computer systems, a byte is a unit of data that is eight binary digits long. Bytes are often used to represent a ...

  • network-attached storage (NAS)

    Network-attached storage (NAS) is dedicated file storage that enables multiple users and heterogeneous client devices to retrieve...

Close