Cascade¶
Definition of cascade protocol implementation.
This module provides an implementation of the cascade protocol for error correction. The protocol must be provided with a lower-layer protocol for key generation, such as BB84. Also included in this module are a function to pair protocol instances (required before the start of transmission) and the message type used by the protocol.
- class src.qkd.cascade.Cascade(own: QKDNode, name: str, w=4, role=- 1, secure_params=100)¶
Implementation of cascade error correction protocol.
The cascade protocol uses checksums to determine if there are errors in a generated key and pinpoint the errors. The protocol exists in 3 states:
initialization step of protocol
generating block
end
- own¶
node that protocol instance is attached to.
- Type:
- name¶
label for protocol instance.
- Type:
str
- w¶
cascade parameter.
- Type:
int
- role¶
differentiates “alice” and “bob” protocols.
- Type:
int
- secure_params¶
security parameter.
- Type:
int
- state¶
current state of protocol.
- Type:
int
- keylen¶
lenght of keys to generate.
- Type:
int
- frame_len¶
length of frame to use to generate keys.
- Type:
int
- frame_num¶
frame number.
- Type:
int
- run_time¶
time to run protocol.
- Type:
int
- bits¶
bits to operate on (received from BB84).
- Type:
List[int]
- t1¶
cascade parameter.
- Type:
int
- t2¶
cascade parameter.
- Type:
int
- k1¶
cascade parameter.
- Type:
int
- checksum_tables¶
lists of generated checksums.
- Type:
List[List[int]]
- another_checksums¶
checksums of paired protocol.
- Type:
List[List[int]]
- index_to_block_id_lists¶
store block ids.
- Type:
List
- block_id_to_index_lists¶
store index ids.
- Type:
List
- time_cost¶
time penalty for key generation.
- Type:
int
- setup_time¶
time of cascade protocol setup.
- Type:
int
- start_time¶
time to start generating corrected keys.
- Type:
int
- end_time¶
time to stop generating keys.
- Type:
int
- valid_keys¶
list of keys generated.
- Type:
List[int]
- throughput¶
protocol throughput in bits/s.
- Type:
float
- error_bit_rate¶
rate of errors in finished keys.
- Type:
float
- latency¶
average latency of generated keys.
- Type:
int
- disclosed_bits_counter¶
counts revealed bits.
- Type:
int
- privacy_throughput¶
throughput of not revealed bits.
- Type:
int
- check_checksum(key_id: int) bool¶
Method to check a checksum.
- Parameters:
key_id (int) – key id to check checksums for.
- Side Effects:
May return keys to upper protocol. WILL send a KEY_IS_VALID method to other cascade protocols.
- create_checksum_table() None¶
Method to create checksum tables.
Initialize checksum_table, index_to_block_id, and block_id_to_index after get key from BB84.
- Side Effects:
Will modify index_to_block_id_lists, block_id_to_index_lists, and checksum_tables attributes.
- end_cascade()¶
Method to end cascade protocol.
- generate_key(keylen: int, frame_num=inf, run_time=inf) None¶
Method to start key generation.
The process for generating keys is:
Generate 10000 bits key to measure error rate at 0 pass
Generate keylen bits key at 1st pass
- Parameters:
keylen (int) – length of key to generate.
frame_num (int) – number of keys to generate (default inf).
run_time (int) – max simulation time allowed for key generation (default inf).
- interactive_binary_search(key_id: int, pass_id: int, block_id: int, start: int, end: int) None¶
Method to search for errors in key.
Split block[start:end] to block[start:(start+end)/2], block[(start+end)/2,end]. Ask checksums of subblock from sender.
- Parameters:
key_id (int) – id of key to check.
pass_id (int) – id of pass to check.
block_id (int) – id of block to check.
start (int) – index to start checking at.
end (int) – index to stop checking at.
- Side Effects:
Will send SEND_FOR_BINARY messages to other protocol.
- performance_measure() None¶
Method to record performance metrics.
- pop(info: int) None¶
Function called by BB84 when it creates a key.
- Parameters:
info (int) – key received.
- push(keylen: int, frame_num=inf, run_time=inf) None¶
Method to receive key generation events.
Defers to generate_key method.
- received_message(src: str, msg: Message) None¶
Method to receive messages from other protocol instance.
Different messages will cause different actions.
- Parameters:
src (str) – name of node that sent the message.
msg (Message) – message received.
- send_by_cc(message: CascadeMessage) None¶
Method to send classical messages.
- class src.qkd.cascade.CascadeMessage(msg_type: Enum, receiver: str, **kwargs)¶
Message used by cascade protocols.
This message contains all information passed between cascade protocol instances. Messages of different types contain different information.
- msg_type¶
defines the message type.
- Type:
- receiver¶
name of destination protocol instance.
- Type:
str
- key¶
initial key sent to establish parameters (if msg_type == KEY).
- Type:
int
- k¶
cascade parameter (if msg_type == PARAMS).
- Type:
int
- keylen¶
length of keys to request from BB84 (if msg_type == PARAMS or GENERATE_KEY).
- Type:
int
- frame_num¶
number of keys to request (if msg_type == PARAMS or GENERATE_KEY).
- Type:
int
- run_time¶
runtime for BB84 (if msg_type == PARAMS or GENERATE_KEY).
- Type:
int
- key_id¶
key being processed (if msg_type == CHECKSUMS or SEND_FOR_BINARY or RECEIVE_FOR_BINARY or KEY_IS_VALID).
- Type:
int
- checksums¶
checksum results (if msg_type == CHECKSUMS).
- Type:
int
- pass_id¶
pass number (if msg_type == SEND_FOR_BINARY or RECEIVE_FOR_BINARY).
- Type:
int
- block_id¶
block number (if msg_type == SEND_FOR_BINARY or RECEIVE_FOR_BINARY).
- Type:
int
- start¶
starting position in key (if msg_type == SEND_FOR_BINARY or RECEIVE_FOR_BINARY).
- Type:
int
- end¶
ending position in key (if msg_type == SEND_FOR_BINARY or RECEIVE_FOR_BINARY).
- Type:
int
- checksum¶
checksum result (if msg_type == RECEIVE_FOR_BINARY).
- Type:
int
- class src.qkd.cascade.CascadeMsgType(value, names=None, *, module=None, qualname=None, type=None, start=1, boundary=None)¶
Defines possible message types for cascade.