A system and method links first and second computers of a network to implement a single signon feature. The user has a first username for accessing the first computer and a second username for accessing the second computer. The first computer generates a link request having a plaintext component including the first username and the second username and an encrypted component formed by encrypting the plaintext component using an encryption process and a secret. The link request is sent to the second computer, which validates the unencrypted information then generates an encryption result by encrypting the unencrypted information using the encryption process and a second secret known to the second computer and associated with the first network computer. The second computer compares the encryption result with the encrypted component of the incoming link request to determine whether the link request is valid.