CipherLinx® incorporates an encryption algorithm based on Skipjack, an algorithm developed by the US National Security Agency (NSA). CipherLinx expands the data block from 64-bits to 128-bits. Skipjack uses an 80-bit key to encrypt a 64-bit data block. CipherLinx uses an 80-bit key to encrypt a 128-bit data block. This allows CipherLinx to use 80 integrity bits for secure authentication and a 40-bit counter. 80 integrity bits means the chances that a modified transmission will be accepted are one in 280. It would take 890 years to roll over at the fastest rate, at which point the user will need to create a new key. This ensures that the same data will never be sent twice. Independent Security Evaluators (ISE) helped Linx design the algorithm and gave the result a glowing review. ISE employees have testified before Congress on electronic security. According to ISE, “…the CipherLinx protocol in the HS Series is well-designed and is an excellent choice for applications requiring a secure unidirectional link.”