[cm/prv/] with Streamlined NTRU Prime 761 + X25519.
=> NTRU Prime
=> X25519
It is a concatenation of SNTRUP and X25519 private keys.

    prv-sntrup761-x25519.tcl {
        {field . {map} len=~}
        {field a {str} =sntrup761-x25519}
        {field v {bin} len=1795}
    }