TEA for real-life embedded project?

Hi,

I'm developing a project which involves sending some small (at most 64
bytes) encrypted data packets to a microcontroller by an application. The
software never encrypts any packets, it just sends one of the previously
prepared and stored ones. This means that:
1. A chosen-plaintext attack is impossible,
2. A chosen-ciphertext attack is impossible (practically),
3. There is a possibility of at most a few hundred ciphertexts for which
some parts of the corresponding plaintexts are known.

Given such circumstances, would using the TEA cipher be unwise?
Unfortunately the project requires decryption speed which is hard to obtain
using AES.

thanks
SM


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