algorithm
board
cipher
code
conceal
cryptography
cryptovariable
cypher
decrypt
decryption
disguised
disks
encipherment
encryption
figure
index
information
key
label
message
number
numbers
numeral
numeral character
numerals
numeric character
operation
plain
procedure
secret
security
series
size
steps
substitution
technical
text
triangle
unreadable
yellow
zero