Related Clues:

• Type of ring
• Mail-away ring
• Kind of ring
• One gaining intelligence, maybe
• Cryptogram solving device
• Kind of promotional ring once offered by Ovaltine
• Translator of 'The German Eating Fish'
• Certain cracker
• The interpreter of 'Animals Catching Fish'
• One interpreting cipher
• This person decrypts
• Data converter
• After end of year, old communist upset GCHQ worker perhaps
• Eg, digital to analogue converter
• Cryptologist