A global cast of characters for cryptography

Based on this proposal, here is a list of updated character names for cryptography discussions. See also: Origins and meanings of updated names.

Updated name	Original name	Description (derived from Alice and Bob)
Alix	Alice	Generic character who generally wants to exchange a message or cryptographic key with Bo.
Bo	Bob	Generic character who generally wants to exchange a message or cryptographic key with Alix.
Caro	Carol, Carlos, or Charlie	A generic third participant.
Chux	Chuck or Chad	A third participant, usually of malicious intent.
Cray	Craig	A password cracker, often encountered in situations with stored passwords.
Davon	Dan, Dave, or David	A generic fourth participant.
Eri	Erin	A generic fifth participant, but rarely used, as "E" is usually reserved for Evan.
Evan	Eve or Yves	An eavesdropper, who is usually a passive attacker. While they can listen in on messages between Alix and Bo, they cannot modify them. In quantum cryptography, Evan may also represent the environment.
Fayzi	Faythe	A trusted advisor, courier, or intermediary. Fayzi is used infrequently and is associated with faith and faithfulness. Fayzi may be a repository of key services or courier of shared secrets.
Frankie	Frank	A generic sixth participant.
Gracen	Grace	A government representative. For example, Gracen may try to force Alix or Bo to implement backdoors in their protocols. Gracen may also deliberately weaken standards.
Heike	Heidi	A mischievous designer for cryptographic standards, but rarely used.
Iva	Ivan	An issuer, mentioned first by Ian Grigg in the context of Ricardian contracts.
Jude	Judy	A judge who may be called upon to resolve a potential dispute between participants.
Mallox	Mallory, Mallet, or Darth	A malicious attacker. Associated with Truva, an intruder. Unlike the passive Evan, Mallox is an active attacker (often used in man-in-the-middle attacks) who can modify messages, substitute messages, or replay old messages. The difficulty of securing a system against a Mallox is much greater than against an Evan.
Mico	Michael or Mike	Used as an alternative to the eavesdropper Evan, from microphone.
Niaj	Niaj	An alternative to the eavesdropper Evan in several South Asian nations.
Oli	Olivia	An oracle, who responds to queries from other participants. Oli often acts as a "black box" with some concealed state or information or as a random oracle.
Osher	Oscar	An opponent, similar to Mallox, but not necessarily malicious.
Pema	Peggy or Pat	A prover, who interacts with the verifier to show that the intended transaction has actually taken place. Pema is often found in zero-knowledge proofs.
Rudo	Rupert	A repudiator, who appears for interactions that desire non-repudiation.
Syd	Sybil	A pseudonymous attacker, who usually uses a large number of identities. For example, Syd may attempt to subvert a reputation system.
Tran	Trent or Ted	A trusted arbitrator, who acts as a neutral third party.
Truva	Trudy	An intruder.
Vero	Victor or Vanna	A verifier, who requires proof from the prover.
Wael	Walter	A warden, who may guard Alix and Bo.
Wen	Wendy	A whistleblower with privileged access capable of divulging information.

For interactive proof systems, there are other characters:

Updated name	Original name	Description (derived from Alice and Bob)
Artha and Merle	Arthur and Merlin	Merle provides answers, and Artha asks questions. Merle has unbounded computational ability (like the wizard Merlin). In interactive proof systems, Merle claims the truth of a statement, and Artha questions them to verify the claim.
Pau and Ora	Paul (after Paul Erdős) and Carole (anagram of oracle)	Pau asks questions, and Ora provides answers. In the solution of the Twenty Questions problem, Pau asked questions, and Ora answered them. Pau and Ora were also used in combinatorial games in the roles of pusher and chooser.
Artha and Beza	Arthur and Bertha	Artha is the left, black, or vertical player, and Beza is the right, white, or horizontal player in a combinatorial game. Additionally, Artha, given the same outcome, prefers a game to take the fewest moves. Contrarily, Beza prefers a game to take the most moves.

Optional citation

If you use these updated names in your work, until these names become the norm, your readers might benefit from some context. Here's a citation you can choose to include:

This work uses the global cast of characters for cryptography.

Proposal: Toward a global cast of characters for cryptography

The history of Alice and Bob

Who are Alice and Bob? They are the first two of what would eventually grow to become a comprehensive cast of characters used to illustrate cryptographic concepts. Specifically, we use these characters in discussions about entities trying to communicate securely using cryptographic systems and protocols.

For example, with the advent of this cast of characters, instead of saying, “Person A sends a message to Person B,” we could now say, “Alice sends a message to Bob,” humanizing and concretizing the scenario.

The original Alice and Bob characters were first documented by Ron Rivest, Adi Shamir, and Leonard Adleman in their 1978 paper, "A Method for Obtaining Digital Signatures and Public-key Cryptosystems." The fuller cast of characters was fleshed out by Bob Schneier in his 1994 book, "Applied Cryptography: Protocols, Algorithms, and Source Code in C."

Imagining the future of communication

In 1978, when Rivest, Shamir, and Adleman published their paper, there was no internet. Digital communication was a concept of science fiction. People did business in person or over the phone.

However, there were cryptographers of the time who conceived of a future in which remote digital communication would be possible—and they were planning for it.

I certainly imagined purely electronic offices. Or buying and selling from a home terminal. I rather imagined we were moving forward, technically, into a future in which either technology could be used to protect the individual, or technology could be used to assault the individual.

— Whitfield Diffie, co-inventor of Diffie-Hellman-Merkle key exchange, a cryptographic method for securely exchanging encryption keys over a public network

I could foresee a world in which buying a loaf of bread would involve an electronic funds transfer.

— Martin Hellman, co-inventor of Diffie-Hellman-Merkle key exchange

But they [Diffie, Hellman, and Merkle] also had the genius of knowing what might be done to protect our privacy, to protect commerce in such a future.

— Leonard Adleman, co-inventor of the RSA algorithm

Vision becomes reality

As just one example, today, the Transport Layer Security (TLS) protocol is used to encrypt data in transit between clients and servers. TLS supports a range of key exchange mechanisms, including Elliptic Curve Diffie-Hellman (ECDHE) and Ephemeral Diffie-Hellman (DHE), both even more secure evolutions of the original Diffie-Hellman-Merkle key exchange.

When billions of people worldwide use web and mobile apps to connect and communicate, most apps use TLS to enable secure client-server communication.

Not only are we buying bread and working in "electronic offices," secure digital communication has enabled global connections at a scale that people might only have dreamt of 45 years ago.

An update to reflect the global community

The original cast of Alice and Bob characters serves cryptography well and plays a role in helping people from around the world communicate about cryptographic topics.

This proposal suggests updating character names to reflect the global impact of cryptography and the global community's contributions to this study and practice.

People can choose to use updated character names in place of original character names.

Get the list
See A global cast of characters for cryptography.

How were the updated names selected?

Names were selected based on the following criteria:

• Enables a global community to see itself reflected in discussions when learning about, creating, and using cryptographic solutions

• Includes at least the first two letters of the original character or role name

  This is meant to help people with recall when transitioning to using updated names.

• Lends itself to gender neutrality

  This removes the need to specify gender unless it's integral to the topic. This can lead to simplified communication as people can use a single set of singular gender-neutral pronouns: they, their, and them and their forms.

  Use of singular gender-neutral pronouns is increasingly becoming the standard for technical documentation. See Gender-neutral pronouns in the "Google developer documentation style guide."

Origins and meanings of updated names

Here's the list of updated names and their origins and meanings. I compiled names, origins, and meanings based on internet research.

I am certain this work contains flaws. For these unintentional flaws, I sincerely apologize in advance.

I humbly request the community's feedback to help improve upon this list and correct errors.

Updated name	Updated name origin and meaning	Original name
Alix	Origin: French Meaning: Noble	Alice
Artha	Origin: Sanskrit Meaning: Riches, wealth	Arthur
Beza	Origin: Ethiopian/Amharic Meaning: Payment, redemption	Bertha
Bo	Origin: Chinese Meaning: Wave	Bob
Caro	Origin: Italian Meaning: Dear, precious	Carol, Carlos, or Charlie
Chux	Origin: None Meaning: None	Chuck or Chad
Cray	Origin: Gaelic Meaning: Curly, prolific	Craig
Davon	Origin: English Meaning: Form of David, meaning beloved, friend	Dan, Dave, or David
Eri	Origin: Japanese Meaning: Blessed prize or reason	Erin
Evan	Origin: Welsh Meaning: Gift, graciousness	Eve or Yves
Fayzi	Origin: Arabic Meaning: Abundance	Faythe
Frankie	Origin: English Meaning: Free	Frank
Gracen	Origin: English Meaning: Steward	Grace
Heike	Origin: German Meaning: Estate rule	Heidi
Iva	Origin: Slavic Meaning: Willow	Ivan
Jude	Origin: English, Hebrew Meaning: Praised	Judy
Mallox	Origin: None Meaning: None	Mallory, Mallet, or Darth
Merle	Origin: Estonian Meaning: Sea	Merlin
Mico	Origin: Native American (Choctaw) Meaning: Chief, leader	Michael or Mike
Niaj	Origin: Sanskrit Meaning: Knowledge, leadership, fairness	Niaj
Oli	Origin: Hawaiian Meaning: Song	Olivia
Ora	Origin: Hebrew / Latin Meaning: Light / Pray	Carole (anagram of oracle)
Osher	Origin: Hebrew Meaning: Happiness	Oscar
Pau	Origin: Chinese Meaning: Treasure, jewel	Paul
Pema	Origin: Tibetan Meaning: Lotus	Peggy or Pat
Rudo	Origin: Zimbabwe Shona Meaning: Love	Rupert
Syd	Origin: English Meaning: Short for Sydney	Sybil
Tran	Origin: Vietnamese Meaning: Peace, calm	Trent or Ted
Truva	Origin: Turkish Meaning: Referring to the ancient city of Troy	Trudy
Vero	Origin: Malagasy Meaning: A tall grass	Victor or Vanna
Wael	Origin: Arabic Meaning: Refuge, shelter	Walter
Wen	Origin: Chinese Meaning: Literature, culture, writing	Wendy

Provide feedback

The success of this proposal depends on constructive feedback and adoption by the 🌏🌍🌎 community.

To provide feedback on this proposal, please open an issue.

If you support this proposal or use the updated cast of characters in your work, consider st⭐️rring this repo.

When contributing to this repo, please follow the community code of conduct.

Gratitude

• Thank you to P.S. for opening my eyes to the need for more global representation in example person names in technical documentation.

• Thank you to the "Google developer documentation style guide" for providing their list of Example person names, which helped inspire this work.