PATENT CLAIM ANALYSIS

Application Number: 15957894
Application Type: Utility
Filing Date: 2018-04
Publication Date: 2018-08
Patent Classification: ["380", "028000"]

Abstract:
A format-preserving cipher including an encryption and a decryption scheme supporting non-linear access to input data by allowing the selection of portions of data from a potentially larger dataset to be encrypted, thus avoiding a necessarily sequential access into the input plaintext data. The cipher first defines a forward mapping from the allowable ciphertext values to an integer set of the number of such allowable ciphertext values, and a corresponding reverse mapping. It also supports exclusion of a certain set of characters from the ciphering process. An encryption algorithm is provided that encrypts the input plaintext data while preserving its original format and length, and a corresponding decryption algorithm is provided. The cipher advantageously embodies the encryption and decryption of multi-byte values, composite datasets, and credit card numbers, thus fitting a variety of industrial needs.

Claim (Index 10):
A system of format-preserving ciphering, comprising:\n (a) at least one portion of data to be ciphered; (b) a forward mapping from N allowable ciphertext values to an integer set {0 . . . N\u22121}, and a corresponding reverse mapping from said integer set {0 . . . N\u22121} to corresponding said N allowable ciphertext values, said allowable ciphertext values being non-contiguous; (c) said at least one portion iteratively accessed in increments of size S bits, where S is set according to a downstream business process utilizing said format-preserving ciphering; (d) a key-stream generated by utilizing a block cipher based on advanced encryption standard (AES) operating in CTR stream mode, said key-stream iteratively accessed in increments of said size S bits; (e) a limiter value L determined as the difference of 2 S  and (2 S  modulo N); (f) an encryption module for encrypting said at least one portion by taking the sum of said forward mapping of said accessed portion in (c) above and modulo N of said accessed key-stream value in (d) above, taking modulo N of said sum to produce a final sum, and taking said reverse mapping of said final sum; (g) said encryption module ignoring any said accessed key-stream value from said encrypting if said key-stream value is greater than or equal to said limiter value L; (h) said encryption module skipping zero or more combinations of said S bits in said at least one portion, from said encrypting; (i) a decryption module for decrypting said at least one portion by taking the difference of said forward mapping of said accessed portion in (c) above and modulo N of said accessed key-stream value in (d) above, taking modulo N of said difference, if said difference is less than 0 then adding N to said difference to produce a final difference, and taking said reverse mapping of said final difference; (j) said decryption module ignoring any said accessed key-stream value from said decrypting if said key-stream value is greater than or equal to said limiter value L; and (k) said decryption module skipping zero or more combinations of said S bits in said at least one portion, from said decrypting.

Metadata:
- Claim Count in Document: 50.0
- Percentile: 91.0
- Lexical Diversity: 1.78049
- Patent Class: 380.0
- Transitional Phrase Type: open
- Component Type: 1
- Foreign Priority: False
- Related Applications: ['15089908', '15200635', '14557464', '09937634', '13189936']

Analysis Scores:
- 35 USC 101 Eligibility (BERT): 0.443159623605639
- 35 USC 102 Novelty (BERT): 0.6186701615066917
- Combined Prediction Score: 0.4607106773957443
- Mean Citation Score: 434.06907400000017
- Max Citation Score: 559.10657
- Similarity Product: 532.7958741085779

Labels:
- Claim Label 101: 1
- Claim Label 102: 1
- Claim Label 103: 1
- Claim Label 112: 1
- Combined Label: 1
- Label 101 Adjusted: 1

Dataset: test