I have found in a Wireless Sensor Networks security paper, operations where cryptographic hash functions are elevated to the power of 2 and to the power of 3 (i.e. h^2(x) and h^3(x)).

This might be a very simple question but I haven't found this notation in other literature. I wonder: does this notation mean that you need to compute the hash twice or thrice (i.e. h(h(x)) and h(h(h(x)))?

In the paper, h(.) is defined as a collision free one-way hash function.

I have found in a Wireless Sensor Networks security paper, operations where cryptographic hash functions are elevated to the power of 2 and to the power of 3 (i.e. $h^2(x)$ and $h^3(x)$).

This might be a very simple question but I haven't found this notation in other literature. I wonder: does this notation mean that you need to compute the hash twice or thrice (i.e. $h(h(x))$ and $h(h(h(x)))$?

In the paper, $h$ is defined as a collision free one-way hash function.

I have found in a Wireless Sensor Networks security paper, operations where cryptographic hash functions are elevated to the power of 2 and to the power of 3 (i.e. h^2(x) and h^3(x)). This might be a very simple question but I havent found this notation in other literature and I wonder, are these simple computing the hash twice and thrice (i.e. h(h(x)) and h(h(h(x)))?

In the paper, h(.) is defined as a collision free one-way hash function.

Thanks in advance

I have found in a Wireless Sensor Networks security paper, operations where cryptographic hash functions are elevated to the power of 2 and to the power of 3 (i.e. h^2(x) and h^3(x)).

This might be a very simple question but I haven't found this notation in other literature. I wonder: does this notation mean that you need to compute the hash twice or thrice (i.e. h(h(x)) and h(h(h(x)))?

In the paper, h(.) is defined as a collision free one-way hash function.