Encryption of slice partials

A distributed storage (DS) unit included in a distributed storage network (DSN) including a plurality of DS units, the DS unit comprising:

• a computing core including a processor and associated memory;
• a communications interface, coupled to the computing core, and configured to receive a rebuilding request indicating that the DS unit is to provide an encrypted partial slice to a requesting DS unit included in the DS network;
• the computing core configured to:
• determine key pairing requirements associated with the rebuilding request;
• select an even number of key pairing entities based on the key pairing requirements, the even number of key pairing entities being fewer than a decode threshold number of key pairing entities;
• generate shared secret keys corresponding to each of the even number of key pairing entities;
• generate an encrypted partial slice by encrypting a partial slice associated with the DS unit using the shared secret keys corresponding to each of the even number of key pairing entities;
• and
• transmit the encrypted partial slice to the requesting DS unit in accordance with a rebuilding topology.

A distributed storage network (DSN) comprising:

• a plurality of distributed storage (DS) units;
• a requesting DS unit configured to transmit a rebuilding request to at least one other DS unit, the rebuilding request indicating that the at least one other DS unit is to provide an encrypted partial slice to the requesting DS unit;
• the at least one other DS unit configured to respond to the rebuilding request by:
• determining key pairing requirements associated with the rebuilding request;
• selecting an even number of key pairing entities based on the key pairing requirements, the even number of key pairing entities being fewer than a decode threshold number of key pairing entities;
• generating shared secret keys corresponding to each of the even number of key pairing entities;
• generating an encrypted partial slice by encrypting a partial slice associated with the at least one other DS unit using the shared secret keys corresponding to each of the even number of key pairing entities;
• and
• transmitting the encrypted partial slice to the requesting DS unit in accordance with a rebuilding topology.