This article is meant to provide an additional point of view, applying known knowledge, to supply keys that have a series of non-repeating digits, in a manner that is not usually thought of. Traditionally, prime numbers are used in encryption as keys that have non-repeating sequences. Non-repetition of digits in a key is very sought after in encryption. Uniqueness in a digit sequence defeats decryption by method. In searching for methods of non-decryptable encryption as well as ways to provide unique sequences, other than using prime numbers, the idea of using repeating decimals came to me. Applied correctly, a repeating decimal series of sufficient length will stand in as well for a prime number. This is so, because only numbers prime to each other will produce repeating decimals and; within the repeating sequence there is uniqueness of digit sequence.