tf.raw_ops.StringToHashBucketStrong
Converts each string in the input Tensor to its hash mod by a number of buckets.
tf.raw_ops.StringToHashBucketStrong( input, num_buckets, key, name=None )
The hash function is deterministic on the content of the string within the process. The hash function is a keyed hash function, where attribute key
defines the key of the hash function. key
is an array of 2 elements.
A strong hash is important when inputs may be malicious, e.g. URLs with additional components. Adversaries could try to make their inputs hash to the same bucket for a denial-of-service attack or to skew the results. A strong hash can be used to make it difficult to find inputs with a skewed hash value distribution over buckets. This requires that the hash function is seeded by a high-entropy (random) "key" unknown to the adversary.
The additional robustness comes at a cost of roughly 4x higher compute time than tf.string_to_hash_bucket_fast
.
Examples:
tf.strings.to_hash_bucket_strong(["Hello", "TF"], 3, [1, 2]).numpy() array([2, 0])
Args | |
---|---|
input | A Tensor of type string . The strings to assign a hash bucket. |
num_buckets | An int that is >= 1 . The number of buckets. |
key | A list of ints . The key used to seed the hash function, passed as a list of two uint64 elements. |
name | A name for the operation (optional). |
Returns | |
---|---|
A Tensor of type int64 . |
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Licensed under the Creative Commons Attribution License 3.0.
Code samples licensed under the Apache 2.0 License.
https://www.tensorflow.org/versions/r2.4/api_docs/python/tf/raw_ops/StringToHashBucketStrong