摘要 |
Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for authenticating a communications source. In one aspect, a method includes decrypting a symbol that was received over a particular communications channel. The symbol is decrypted using a decryption key that is assigned to a particular endpoint that is assigned the particular communications channel. A measure of error is computed for the decrypted symbol. In turn, a determination is made whether the measure of error exceeds a threshold error measure. If the measure of error does not exceed the threshold error measure the decrypted symbol is identified as a valid symbol transmitted by the particular endpoint, and logged as such. If the measure of error exceeds the threshold error measure, the decrypted symbol is identified as a symbol from a different endpoint; and |