TOTP: Time Based One Time Passwords | Security Encyclopedia (2024)

FAQs

What is time-based one-time password TOTP standards? ›

A Time-Based One-Time Password (TOTP, or OTP) is a string of dynamic digits of code, whose change is based on time. Often, these appear as sic-digit numbers that regenerate every 30 seconds. TOTPs are derived from a secret seed password given at user registration in the form of QR code or in plaintext.

Time-based one-time password (TOTP) is a computer algorithm that generates a one-time password (OTP) using the current time as a source of uniqueness. As an extension of the HMAC-based one-time password algorithm (HOTP), it has been adopted as Internet Engineering Task Force (IETF) standard RFC 6238.

OTP generation algorithms typically make use of pseudorandomness or randomness to generate a shared key or seed, and cryptographic hash functions, which can be used to derive a value but are hard to reverse and therefore difficult for an attacker to obtain the data that was used for the hash.

This is a type of one-time password that is algorithmically generated with a shared secret key and an incrementing counter. The counter is increased each time an OTP is generated and both the server and the authentication device maintain the counter.

Google Authenticator is a software-based authenticator by Google. It implements multi-factor authentication services using the time-based one-time password (TOTP; specified in RFC 6238) and HMAC-based one-time password (HOTP; specified in RFC 4226), for authenticating users of software applications.

Why is a one-time password safe? The OTP feature prevents some forms of identity theft by making sure that a captured username/password pair cannot be used a second time. Typically the user's login name stays the same, and the one-time password changes with each login.

The TOTP algorithm, codified in RFC 6238, relies on a shared secret key for authentication. That key, combined with the wall clock time and a special cryptographic algorithm, produces a short OTP code (typically 6 digits) that changes periodically (typically every 30 seconds).

Considering that the TOTP changes every 30 seconds, the possibility for a hacker to intercept it is very small. Leveraging this extra layer of security helps protect users' accounts and sensitive information from unauthorized access and data breaches.

Shared Secret: A unique, random string of characters generated at the time when TOTP is enabled for an account. Typically, the server generates this secret and shares it securely with the client. It's often encoded in a QR code that the user scans with their authenticator app.

An example of this OTP generation is the Time Based OTP Algorithm (TOTP) described as follows: Backend server generates the secret key. The server shares secret key with the service generating the OTP. A hash based message authentication code (HMAC) is generated using the obtained secret key and time.

How is an OTP typically generated? ›

OTPs are generated using algorithms and time-sensitive variables. Once the OTP is created and sent as an additional MFA source, the code is copied to the authentication window or other form that verifies the code with the authentication server. The user is then allowed access to their account.

A TOTP is generated by an app or any other device that supports TOTP and is valid only for a short duration (usually 30 seconds), and is regenerated every 30 seconds. The following apps can be downloaded on PCs or phones to generate the TOTP: Google® Authenticator available on Google Play (WEB) and App store (WEB).

TOTP stands for Time-based One-Time Passwords and is a common form of two-factor authentication (2FA). Unique numeric passwords are generated with a standardized algorithm that uses the current time as an input.

Disadvantages of One-Time Passwords

A user may also be unable to access the OTP. Some emailed OTPs may be delayed or end up in a Spam folder. If a user loses a physical token, they've lost access to their OTP.

Cybercriminals are also turning to automation to help access OTPs, with one report finding that bots had a success rate of around 80% when it came to stealing one-time passwords once they had the victim's phone number.

What is TOTP? Time-based One-time Password (TOTP) is a time-based OTP. The seed for TOTP is static, just like in HOTP, but the moving factor in a TOTP is time-based rather than counter-based. The amount of time in which each password is valid is called a timestep.

Result: LastPass generates a 6-digit, time-based one-time passcode (TOTP), using the SHA-1 algorithm, and the TOTP changes every 30 seconds. Note: The TOTP automatically populates in the site's "one-time passcode" field if the site is stored in your vault and has a secret key associated.

For the TOTP tool, the default validity time setting is 5 minutes. The validity window is 2.5 minutes before and 2.5 minutes after the password's received timestamp, plus 30 seconds.

One Time Password Examples

Once the user has begun his login attempt, filling in his username and the correct password, an SMS OTP is sent to the mobile number connected to his account. The user then enters this code shown on this phone in the login screen, completing the authentication process.