Help us improve your experience.

Let us know what you think.

Do you have time for a two-minute survey?


Authentication Methods in FIPS Mode of Operation


The Juniper Networks Junos operating system (Junos OS) running in FIPS mode of operation allows a wide range of capabilities for users, and authentication is identity-based. The following types of identity-based authentication are supported in the FIPS mode of operation:

Username and Password Authentication over the Console and SSH

In this authentication method, the user is requested to enter the username and password. The device enforces the user to enter a minimum of 10-characters password that is chosen from the 96 human-readable ASCII characters.


The maximum password length is 20 characters.

In this method, the device enforces a timed access mechanism—for example, first two failed attempts to enter the correct password (assuming 0 time to process), no timed access is enforced. When the user enters the password for the third time, the module enforces a 5-second delay. Each failed attempt thereafter results in an additional 5-second delay above the previous failed attempt. For example, if the fourth failed attempt is a 10-second delay, then the fifth failed attempt is a 15-second delay, the sixth failed attempt is a 20-second delay, and the seventh failed attempt is a 25-second delay.

Therefore, this leads to a maximum of seven possible attempts in a 1-minute period for each getty active terminal. So, the best approach for the attacker would be to disconnect after 4 failed attempts, and wait for a new getty to be spawned. This would allow the attacker to perform roughly 9.6 attempts per minute (576 attempts per hour or 60 minutes). This would be rounded off to 9 attempts per minute, because there is no such thing as 0.6 attempts. Thus the probability of a successful random attempt is 1/96^10, which is less than 1/1 million. The probability of a success with multiple consecutive attempts in a 1-minute period is 9/(96^10), which is less than 1/100,000.

Username and Public Key Authentication over SSH

With SSH public-key authentication, the user provides the username and proves ownership of the private key corresponding to the public key stored on the server. The device supports ECDSA (P-256, P-384, and P-521) and RSA (2048-bit or higher since our RSA implementation is FIPS 186-4 compliant). The probability of a success with multiple consecutive attempts in a 1-minute period is 5.6e7/(2^112).