A method, comprising: receiving, by a Segment Routing node , a protected Segment Routing packet via a network , with said protected Segment Routing packet including: a Segment Routing Header comprising a Segment List with a plurality of segment identifiers (551-554), including a Security Segment Identifier for a secured portion of the protected Segment Routing packet, and a Segments Left value indicating a current segment identifier , wherein the Security Segment Identifier comprises a value based on processing the secured portion using a one-way cryptographic hash function; and an outer Internet Protocol version 6, IPv6, header comprising a Destination Address of the Segment Routing node; authenticating, by the Segment Routing node, the secured portion of the protected Segment Routing packet, with said authenticating including security processing the secured portion to generate an integrity check value, and performing a comparison operation between a first value based on the integrity check value and a second value based on the Security Segment Identifier in the Segment List of the protected Segment Routing packet; and in response to said authenticating confirming the integrity of the secured portion, further processing the protected Segment Routing packet, the processing comprising: reducing the Segments Left value to advance past the current segment identifier and the Security Segment Identifier; and sending the protected Segment Routing packet into the network; wherein the secured portion includes the value of the Destination Address of the protected Segment Routing packet when received by the Segment Routing node. receiving, by a Segment Routing node , a protected Segment Routing packet via a network , with said protected Segment Routing packet including: a Segment Routing Header comprising a Segment List with a plurality of segment identifiers (551-554), including a Security Segment Identifier for a secured portion of the protected Segment Routing packet, and a Segments Left value indicating a current segment identifier , wherein the Security Segment Identifier comprises a value based on processing the secured portion using a one-way cryptographic hash function; and an outer Internet Protocol version 6, IPv6, header comprising a Destination Address of the Segment Routing node; a Segment Routing Header comprising a Segment List with a plurality of segment identifiers (551-554), including a Security Segment Identifier for a secured portion of the protected Segment Routing packet, and a Segments Left value indicating a current segment identifier , wherein the Security Segment Identifier comprises a value based on processing the secured portion using a one-way cryptographic hash function; and an outer Internet Protocol version 6, IPv6, header comprising a Destination Address of the Segment Routing node; authenticating, by the Segment Routing node, the secured portion of the protected Segment Routing packet, with said authenticating including security processing the secured portion to generate an integrity check value, and performing a comparison operation between a first value based on the integrity check value and a second value based on the Security Segment Identifier in the Segment List of the protected Segment Routing packet; and in response to said authenticating confirming the integrity of the secured portion, further processing the protected Segment Routing packet, the processing comprising: reducing the Segments Left value to advance past the current segment identifier and the Security Segment Identifier; and sending the protected Segment Routing packet into the network; reducing the Segments Left value to advance past the current segment identifier and the Security Segment Identifier; and sending the protected Segment Routing packet into the network; wherein the secured portion includes the value of the Destination Address of the protected Segment Routing packet when received by the Segment Routing node. <EOS>