Clef

What Clef does

Clef is a two-factor authentication (2FA) application company founded in 2013 and headquartered in Oakland, California. The company developed and offered a two-factor authentication application, providing organizations with an additional security layer for user authentication beyond passwords. According to firmographic data, Clef operates as a for-profit private company with a small team (1-10 employees), and its website was hosted at getclef.com. Mark Hudnall served as Founder and CTO.

Clef's documented business activity is concentrated in a 2014-2015 window during which it raised venture funding from Marc Bell Ventures, Morado Ventures, and the StartX (Stanford-StartX Fund). The largest disclosed round was a $1.7 million raise in November 2014. Beyond this funding history and the founder/leadership record, the input data does not contain information about Clef's product features, pricing, customer references, go-to-market motion, technology stack, geographic footprint, or financial performance. The absence of any post-2015 capital raises, product updates, leadership changes, partnership announcements, or M&A activity in the provided data is a material gap that prevents deeper analysis and may indicate a wind-down, acquisition, or severely curtailed operations not captured in the aggregated sources.

Name

Clef

Legal name

Rublon

Website

https://getclef.com

Company type

Private

Founded year

2013

Operating status

Operating

Headcount range

1–10 employees

Short description

Clef is a small Oakland-based two-factor authentication application company founded in 2013, offering 2FA solutions to organizations seeking additional authentication security beyond passwords.

Ownership category

akta.pro rank

Headquarters

HQ city

Oakland

HQ country

United States

HQ region

North America

Markets served

GTM type

B2B

Offering type

Software

Cost components

Personnel, Technology or R&D, Marketing or Sales, Operations

Revenue model

1. Subscription Licensing: Rublon operates on a subscription licensing model, charging organizations for MFA protection across users and devices. The platform offers organization-wide deployment capabilities.

Pricing tiers

Go-to-market motion1 record

Distribution channels3 records

Marketing channels7 records

Core offering

Clef is a two-factor authentication application company. It provided mobile-based 2FA software that replaced traditional passwords, allowing users to securely log into websites and applications via their mobile device. The company was founded in 2013 and operated with a small team of 1-10 employees from Oakland, California.

Product overview

Rublon is a unified Multi-Factor Authentication (MFA) platform designed for secure remote access to networks, servers, and applications. The core Rublon MFA platform serves as the central authentication engine, complemented by the Rublon Authenticator mobile app for push notifications and OTP tokens. Agentless MFA capabilities are provided through Rublon App Shield and Rublon Identity Bridge modules. Additional modules include Single Sign-On (SSO), Directory Sync, Access Policies, and Remembered Devices. The platform offers dedicated MFA solutions for specific technologies including Remote Desktop, Windows Logon, Linux, Active Directory, LDAP, RADIUS, SAML, RemoteApp, Entra ID, Windows Server Core, Remote Access Software, and Workgroup Accounts.

Differentiator

Problem solved

Functional benefit

Products and services

• Clef Two-Factor Authentication App Mobile-based two-factor authentication application that enables users to securely log into websites and applications by replacing traditional passwords with their smartphone. The app uses cryptographic key exchange between the mobile device and browser to verify identity.

Quantifiable outcome

• Enterprise deployment can be installed, tested, and operational in under a day across all offices
• +1 more outcomes

Named customers6 records

Segments5 records

Ideal customer profiles1 record

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Integration14 records

Feature7 records

Scale indicators1 record

Recent moves3 records

Expansion highlights2 records

Broad incumbents

• Google Authenticator: Free, widely deployed 2FA OTP application from Google. Comparable product category with effectively unlimited distribution; sets the floor on consumer/developer willingness to pay for 2FA apps.
• Microsoft Authenticator: Free 2FA application bundled into Microsoft's identity ecosystem (Entra ID/Azure AD). Comparable end-user function but embedded in a much larger platform — represents the device-platform-default threat.
• RSA SecurID: Long-established enterprise MFA and identity assurance platform from RSA (Dell Technologies). Comparable authentication product category, targeting large enterprise and government buyers with on-premise options.
• Okta: Identity and access management platform offering MFA, SSO, and lifecycle management. Broader incumbent in the authentication space — overlaps with Clef on MFA but offers a much wider identity portfolio.
• OneLogin: SSO and identity management platform with MFA capabilities. Comparable adjacent identity-and-authentication product, broader portfolio but overlapping buyer.

Emerging players

• LastPass: Password manager with integrated 2FA/MFA features. Comparable on the consumer/developer authentication-adjacent axis; partial overlap with Clef's user base and value proposition.

Direct peers

• Yubico: Hardware authentication (FIDO2/YubiKey) and software MFA provider. Comparable as an authentication-focused vendor, though with a hardware-led differentiator; overlaps Clef on strong-auth use cases.
• Duo Security: Cloud-based MFA and zero-trust security platform acquired by Cisco. Directly comparable product category (2FA/MFA) with similar target customers (SMB and enterprise), though at substantially greater scale.
• Authy: Two-factor authentication mobile app acquired by Twilio. Closely comparable as a 2FA-only application before acquisition; represents the same product archetype Clef pursued.
• Rublon: Multi-factor authentication platform offering MFA for cloud apps, VPNs, servers, and on-premise applications with broad protocol coverage (RDP, SAML, RADIUS, LDAP, AD FS, SSH). Directly comparable to Clef as a dedicated 2FA/MFA product company.

Market position

Strengths3 records

Weaknesses4 records

Competitive moat2 records

Key risks5 records

Key highlights4 records

Customer concentration

• Xx.com/getclef
• GitHubgithub.com/Rublon
• YouTubeyoutube.com/@Rublon
• Facebookfacebook.com/getclef
• LinkedInlinkedin.com/company/clef

Compliance6 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles1 record

Funding overview

Funding rounds3 records

Investors3 records

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Clef